導讀：
主要從4個方面來闡述，1：背景；2：思路；3：代碼實作；4：使用
一：封裝背景，
在做項目的時候，用的JPA ，有些複雜查詢，比如報表用原生的JdbcTemplate ，很不友善，傳參也不友善，如果參數多；需要增加分頁功能，以及結果集自動轉對像等5個常用功能，見第4節
下面兩個圖是開源測試管理軟體 itest 的統計功能，因為SQL複雜，有些有200行，是以才有後面的 JdbcTemplateWrapper；可以在這體驗這些報表（點測試，然後選擇一個項目，然後點度量分析），速度還不錯，
https://itest.work/rsf/site/itest/product/index.html https://itest.work/rsf/site/itest/product/index.html
上面這圖，SQL 就有200行
二：封裝實作思路
（1）實作spring RowMapper 接口，直接把jdbc 結果集轉 JAVA 對像(用的反射，通路量大的業務不推薦用這方式)
（2）不通過 RowMapper 接口, 把JdbcTemplate
傳回的List<Map<String,Object>>
原生JDBC結果集中，字段名，也就是MAP中的KEY，轉換為駝峰規則的JAVA對屬性名,友善前端元件使用，不再中間轉為VO 或
實體類對像後，再返前端;比傳統查詢（多了一個LIST的周遊 ，基本對性能影響不大）
（3）封裝分頁
（4） 在 JdbcTemplateWrapper 中包裝
NamedParameterJdbcTemplate 解決友好傳參的問題,
再封幾個常用的查詢方法，可變長參數，或是以MAP形式傳參數 key 為SQL中的參數名占位符
三：代碼實作
兩個類，ObjectRowMapper 和 JdbcTemplateWrapper
ObjectRowMapper 代碼如下：
package cn.com.mypm.framework.jdbc;
import java.lang.reflect.Field;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.util.StringUtils;
import cn.com.mypm.common.util.CalendaUtilities;
import cn.com.mypm.framework.common.config.PropertiesBean;
/**
*
* <p>标題: RowMapper 接口實作</p>
* <p>業務描述:完成原生結果集到JAVA對像的轉換</p>
* <p>公司:itest.work</p>
* <p>版權:itest 2018</p>
* @author itest andy
* @date 2018年6月8日
* @version V1.0
*/
@SuppressWarnings("rawtypes")
public class ObjectRowMapper implements RowMapper {
private Class<?> objectClass;
private String[] columnNames = null;
private Field[] fields ;
///緩存 目前結果集字對段和目前class的 Field的對應關系，
private Map<String ,Field> currQueryFieldMap ;
//緩存目前結果集，字段和 JAVA屬性名的對應關系 ，按脫峰規則做的轉換
private Map<String ,String> fieldClassMap ;
private Boolean isConvertSwitch = null;
// MYSQL 是否區分大小寫的标記，要是區轉，要把結果集中，字段名，大寫轉為小寫
private String mysqlLowerCaseTableNames = null;
private static Log logger = LogFactory.getLog(ObjectRowMapper.class);
//緩存某個class 已處理過的字段映射到屬性名的關系，避免同一個類每次重新處理，第一個KEY 為類名
private static Map<String, Map<String, String>> dbColumnClassFieldMap = new ConcurrentHashMap<String, Map<String, String>>();
public ObjectRowMapper(Class<?> objectClass) {
this.objectClass = objectClass;
fields = objectClass.getDeclaredFields();
}
public void clean(){
if(currQueryFieldMap!=null){
currQueryFieldMap.clear();
currQueryFieldMap = null;
}
if(fieldClassMap!=null){
fieldClassMap.clear();
fieldClassMap = null;
}
if(fields!=null){
fields = null;
}
if(columnNames!=null){
columnNames = null;
}
}
/**
* 該方法自動将資料庫字段對應到Object中相應字段 要求：
* 字段名嚴格為駝峰形式 == 資料庫字段名去掉下劃線轉為駝峰形式
* 如user_name 轉為userName ，如資料庫字段名，無下劃線
* 就隻能把首字母變為大小寫後的 set ,get
*/
@Override
public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
Object targetObject = null;
try {
targetObject = objectClass.newInstance();
} catch (InstantiationException | IllegalAccessException e) {
logger.error(e.getMessage(), e);
}
if (columnNames == null) {
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
columnNames = new String[columnCount];
for (int i = 0; i < columnCount; i++) {
columnNames[i] = rsmd.getColumnLabel(i + 1);
}
}
isConvertSwitch = true;
if(mysqlLowerCaseTableNames == null){
String lowerCaseNames = PropertiesBean.getInstance().getProperty("conf.mysql.lowerCaseNames");
if(lowerCaseNames==null){
mysqlLowerCaseTableNames = "yes";
}else{
mysqlLowerCaseTableNames = "no";
}
}
if(currQueryFieldMap==null){
currQueryFieldMap = new HashMap<String,Field>(columnNames.length);
for (String columnName : columnNames) {
for (Field field : fields) {
if(isConvertSwitch==null){
if (field.getName().equals(
convertColumnNameToFieldName(columnName))) {
currQueryFieldMap.put(columnName, field);
break;
}
}else{
if(isConvertSwitch){
if(targetObject instanceof CustomRowMapper&&(!((CustomRowMapper)targetObject).isConvert())){
if (field.getName().equals(columnName)) {
currQueryFieldMap.put(columnName, field);
break;
}
}else{
if (field.getName().equals(
convertColumnNameToFieldName(columnName))) {
currQueryFieldMap.put(columnName, field);
break;
}
}
}
}
}
}
}
for (String columnName : columnNames) {
Field field = currQueryFieldMap.get(columnName);
if(field==null){
if(logger.isDebugEnabled()){
logger.debug(objectClass.getName() +"is not property match db columnName:"+columnName );
}
continue;
}
Object value = rs.getObject(columnName);
if (value == null) {
continue;
}
boolean accessFlag = field.isAccessible();
if (!accessFlag) {
field.setAccessible(true);
}
if(fieldClassMap==null){
fieldClassMap = new HashMap<String,String>(columnNames.length);
}
if(fieldClassMap.get(columnName)==null){
fieldClassMap.put(columnName, getFieldClaszName(field));
}
setFieldValue(targetObject, field, rs, columnName,fieldClassMap.get(columnName));
// 恢複相應field的權限
if (!accessFlag) {
field.setAccessible(accessFlag);
}
}
return targetObject;
}
public String convertColumnNameToFieldName(String columnName) {
Map<String, String> fieldMap = dbColumnClassFieldMap.get(objectClass
.getName());
boolean emptyFlg = false;
if (fieldMap == null) {
fieldMap = new HashMap<String, String>();
emptyFlg = true;
}
String classFieldName = fieldMap.get(columnName);
if (classFieldName != null) {
return classFieldName;
}
String columnNameKey = columnName;
//if ("oracle".equals(dbType)||("mysql".equals(dbType)&&"no".equals(mysqlLowerCaseTableNames))) {
columnName = columnName.toLowerCase();
//}
StringBuffer buf = new StringBuffer();
int i = 0;
while ((i = columnName.indexOf('_')) > 0) {
buf.append(columnName.substring(0, i));
columnName = StringUtils.capitalize(columnName.substring(i + 1));
}
buf.append(columnName);
fieldMap.put(columnNameKey, buf.toString());
if (emptyFlg) {
dbColumnClassFieldMap.put(objectClass.getName(), fieldMap);
}
return fieldMap.get(columnNameKey);
}
/**
* 根據類型對具體對象屬性指派
*/
public static void setFieldValue(Object targetObj, Field field,
ResultSet rs, String columnLabel,String fieldClass) {
try {
if ("String".equals(fieldClass)) {
field.set(targetObj, rs.getString(columnLabel));
} else if ("Double".equals(fieldClass)) {
field.set(targetObj, rs.getDouble(columnLabel));
} else if ("Float".equals(fieldClass)) {
field.set(targetObj, rs.getFloat(columnLabel));
} else if ("Integer".equals(fieldClass)) {
field.set(targetObj, rs.getInt(columnLabel));
} else if ("Long".equals(fieldClass)) {
field.set(targetObj, rs.getLong(columnLabel));
} else if ("BigDecimal".equals(fieldClass)) {
field.set(targetObj, rs.getBigDecimal(columnLabel));
} else if ("Date".equals(fieldClass)) {
field.set(targetObj, rs.getDate(columnLabel));
} else if ("Short".equals(fieldClass)) {
field.set(targetObj, rs.getShort(columnLabel));
} else if ("Boolean".equals(fieldClass)) {
field.set(targetObj, rs.getBoolean(columnLabel));
} else if ("Byte".equals(fieldClass)) {
field.set(targetObj, rs.getByte(columnLabel));
} else if ("Timestamp".equals(fieldClass)) {
field.set(targetObj, rs.getTimestamp(columnLabel));
} else if("BigDecimal".equals(fieldClass)) {
field.set(targetObj, rs.getBigDecimal(columnLabel));
}else {
//這裡沒有實作，如有特殊需要處理的在這裡實作
}
} catch (IllegalArgumentException e) {
logger.error(e.getMessage(), e);
} catch (IllegalAccessException e) {
logger.error(e.getMessage(), e);
} catch (SQLException e) {
logger.error(e.getMessage(), e);
}
}
private static String getFieldClaszName(Field field) {
String elemType = field.getType().toString();
if ("class java.lang.String".equals(elemType)
|| elemType.indexOf("char") != -1
|| elemType.indexOf("Character") != -1) {
return "String";
} else if (elemType.indexOf("double") != -1
|| elemType.indexOf("Double") != -1) {
return "Double";
} else if (elemType.indexOf("float") != -1
|| elemType.indexOf("Float") != -1) {
return "Float";
} else if (elemType.indexOf("int") != -1
|| elemType.indexOf("Integer") != -1||elemType.indexOf("BigInteger") != -1) {
return "Integer";
} else if (elemType.indexOf("long") != -1
|| elemType.indexOf("Long") != -1) {
return "Long";
} else if (elemType.indexOf("BigDecimal") != -1) {
return "BigDecimal";
} else if (elemType.indexOf("Date") != -1) {
return "Date";
} else if (elemType.indexOf("short") != -1
|| elemType.indexOf("Short") != -1) {
return "Short";
} else if (elemType.indexOf("boolean") != -1
|| elemType.indexOf("Boolean") != -1) {
return "Boolean";
} else if (elemType.indexOf("byte") != -1
|| elemType.indexOf("Byte") != -1) {
return "Byte";
} else if (elemType.indexOf("Timestamp") != -1) {
return "Timestamp";
}
return "String";
} JdbcTemplateWrapper
package cn.com.mypm.framework.jdbc;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.util.Assert;
import cn.com.mypm.common.dto.PageModel;
import cn.com.mypm.framework.exception.DataBaseException;
/**
*
* <p>标題: JdbcTemplate 包裝器</p>
* <p>業務描述:實作分頁，原生結果集轉對像，原生結果集字段名轉脫峰java 屬性名</p>
* <p>公司:itest.work</p>
* <p>版權:itest 2018</p>
* @author itest andy
* @date 2018年6月8日
* @version V1.0
*/
public class JdbcTemplateWrapper {
private static Log logger = LogFactory.getLog(JdbcTemplateWrapper.class);
private JdbcTemplate jdbcTemplate;
private String dbType = "mysql";
private String showSql = "false";
protected NamedParameterJdbcTemplate namedParameterJdbcTemplate;
private String mysqlLowerCaseTableNames = null;
public JdbcTemplateWrapper() {
super();
}
public JdbcTemplateWrapper(JdbcTemplate jdbcTemplate) {
super();
this.jdbcTemplate = jdbcTemplate;
this.namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate);
}
public JdbcTemplateWrapper(JdbcTemplate jdbcTemplate, String dbType, String showSql) {
super();
this.jdbcTemplate = jdbcTemplate;
this.dbType = dbType;
this.namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate);
this.showSql = showSql;
}
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
/**
* 查詢所有比對的清單
*
* @param sql
* 查詢sql
* @param className
* 對象類型
* @param args
* 查詢參數
* @return
* @author itest andy
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public List queryAllMatchList(String sql, Class clasz, Object[] args) {
Assert.notNull(clasz, "clasz must not be null");
List dataList = null;
RowMapper rowMapper = new ObjectRowMapper(clasz);
dataList = getJdbcTemplate().query(sql, args, rowMapper);
((ObjectRowMapper) rowMapper).clean();
rowMapper = null;
return dataList;
}
/**
* 查詢所有比對的清單
*
* @param sql
* 查詢sql
* @param className
* 對象類型
* @param args
* 查詢參數
* @return
* @author itest andy
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public List queryAllMatchListWithFreePra(String sql, Class clasz, Object... args) {
Assert.notNull(clasz, "clasz must not be null");
List dataList = null;
RowMapper rowMapper = new ObjectRowMapper(clasz);
dataList = getJdbcTemplate().query(sql, args, rowMapper);
((ObjectRowMapper) rowMapper).clean();
rowMapper = null;
return dataList;
}
/**
* 把list map 原生JDBC結果集中，字段名，也就是MAP中的KEY，轉換為駝峰規則的JAVA對屬性名
*
* @param resultList ：JDBC 結果集
* @return 把MAP中的KEY轉換為轉換為駝峰規則的JAVA對屬性名的LIST<map<駝峰規則的JAVA對屬性名形式的KEY,Object>>
* @author itest andy
*/
public void converDbColumnName2ObjectPropName(List<Map<String,Object>> resultList) {
if(resultList!=null&&!resultList.isEmpty()) {
List<Map<String,Object>> convertList= new ArrayList<Map<String,Object>>(resultList.size());
//用于緩存字段名到屬性名的映射，第二條記錄時就不再處理字段名到屬性名的轉換，提升性能
Map<String,String> ColumnNamePropNameMap = null;
if(resultList.size()>1) {
ColumnNamePropNameMap = new HashMap<String,String>();
}
for(Map<String,Object> currMap :resultList) {
if(currMap!=null&&!currMap.isEmpty()) {
Iterator<Entry<String, Object>> currentIt = currMap.entrySet().iterator();
Map tempMap = new HashMap<String,Object>();
convertList.add(tempMap);
while(currentIt.hasNext()) {
Map.Entry<String,Object> me= currentIt.next();
String dbColumnName = me.getKey();
Object value = me.getValue();
if(resultList.size()>1) {
if(ColumnNamePropNameMap.get(dbColumnName)==null) {
String currProName = convertColumnName2OFieldName(dbColumnName);
tempMap.put(currProName, value);
//緩存起來，第二條記錄時就不再處理字段名到屬性名的轉換，提升性能
ColumnNamePropNameMap.put(dbColumnName, currProName);
}else {
tempMap.put(ColumnNamePropNameMap.get(dbColumnName), value);
}
}else {
tempMap.put(convertColumnName2OFieldName(dbColumnName), value);
}
}
}
}
resultList.clear();
for(Map<String,Object> currMap:convertList) {
resultList.add(currMap);
}
convertList.clear();
convertList = null;
}
}
public String convertColumnName2OFieldName(String columnName ) {
if(mysqlLowerCaseTableNames == null){
String lowerCaseNames = PropertiesBean.getInstance().getProperty("conf.mysql.lowerCaseNames");
if(lowerCaseNames==null){
mysqlLowerCaseTableNames = "yes";
}else{
mysqlLowerCaseTableNames = "no";
}
}
if ("oracle".equals(dbType)||("mysql".equals(dbType)&&"no".equals(mysqlLowerCaseTableNames))) {
columnName = columnName.toLowerCase();
}
if("true".equals(mysqlLowerCaseTableNames)) {
columnName = columnName.toLowerCase();
}
StringBuffer buf = new StringBuffer();
int i = 0;
while ((i = columnName.indexOf('_')) > 0) {
buf.append(columnName.substring(0, i));
columnName = StringUtils.capitalize(columnName.substring(i + 1));
}
buf.append(columnName);
return buf.toString();
}
/**
* 查詢所有比對的清單
*
* @param sql
* 查詢sql
* @param className
* 對象類型
* @param paramMap
* 查詢參數
* @return
* @author itest andy
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public List queryAllMatchListWithParaMap(String sql, Class clasz, Map paramMap) {
if (paramMap != null && paramMap.isEmpty()) {
paramMap = null;
}
if ("true".equals(showSql)) {
try {
logger.info(getSqlFromQueryData(sql, paramMap));
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
List resultList = null;
if (clasz == null) {
resultList = namedParameterJdbcTemplate.queryForList(sql, paramMap);
} else {
RowMapper rowMapper = new ObjectRowMapper(clasz);
resultList = namedParameterJdbcTemplate.query(sql, paramMap, rowMapper);
((ObjectRowMapper) rowMapper).clean();
rowMapper = null;
}
return resultList;
}
/**
*
* @param pageModel:
* @param className
* : 從查詢結果集中建構出的類，如為null則pageModel的PageData為List<Map>，
* 不為null則pageModel的PageData為List<className>
* @param columnNameForCount:查詢記錄數時的字段名，一般用主鍵
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public void fillPageModelData(PageModel pageModel, Class className, String columnNameForCount) {
if (pageModel.getHqlParamMap() != null && pageModel.getHqlParamMap().isEmpty()) {
pageModel.setHqlParamMap(null);
}
if (pageModel.getTotal() == 0) {
int totalRows = this.getResultCountWithValuesMap(pageModel.getQueryHql(), columnNameForCount,
pageModel.getHqlParamMap());
pageModel.setTotal(totalRows);
}
if (pageModel.getTotal() == 0) {
pageModel.setRows(new ArrayList());
return;
}
if (pageModel.getPageNo() > 1) {
int pageCount = this.getValidPage(pageModel.getPageNo(), pageModel.getTotal(), pageModel.getPageSize());
if (pageCount < pageModel.getPageNo()) {
pageModel.setPageNo(pageCount);
}
}
int startRow = getStartOfPage(pageModel.getPageNo(), pageModel.getPageSize());
String sql = this.buildPageSql(pageModel.getQueryHql(), startRow, pageModel.getPageSize());
if ("true".equals(showSql)) {
try {
logger.info(getSqlFromQueryData(sql, pageModel.getHqlParamMap()));
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
List dataList = null;
if (className == null) {
dataList = namedParameterJdbcTemplate.queryForList(sql, pageModel.getHqlParamMap());
} else {
RowMapper rowMapper = new ObjectRowMapper(className);
dataList = namedParameterJdbcTemplate.query(sql, pageModel.getHqlParamMap(), rowMapper);
((ObjectRowMapper) rowMapper).clean();
rowMapper = null;
}
pageModel.setRows(dataList);
}
/**
* 多表sql 分頁查詢,多表連查時，才用這個方法，其他請用commonDao的 SQL分頁查詢
*
* @param sql
* @param className
* @param paramMap
* @param pageNo
* @param PageSize
* @param columnNameForCount
* @return
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public List queryAllMatchListWithParaMap(String sql, Class clasz, Map paramMap, int pageNo, int pageSize,
String columnNameForCount) {
if (paramMap != null && paramMap.isEmpty()) {
paramMap = null;
}
if ("true".equals(showSql)) {
try {
logger.info(getSqlFromQueryData(sql, paramMap));
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
// int totalRows = this.getResultCountWithValuesMap(sql,
// columnNameForCount, paramMap);
// if(pageNo>1){
// int pageCount = this.getValidPage(pageNo, totalRows, pageSize);
// }
List resultList = null;
int startRow = getStartOfPage(pageNo, pageSize);
if (clasz == null) {
resultList = namedParameterJdbcTemplate.queryForList(this.buildPageSql(sql, startRow, pageSize), paramMap);
} else {
RowMapper rowMapper = new ObjectRowMapper(clasz);
resultList = namedParameterJdbcTemplate.query(this.buildPageSql(sql, startRow, pageSize), paramMap,
rowMapper);
rowMapper = null;
}
return resultList;
}
private String buildPageSql(String sql, int startRow, int pageSize) {
if ("oracle".equals(this.getDbType())) {
return this.buildOraclePageSql(sql, startRow, pageSize);
} else if ("mysql".equals(this.getDbType())) {
return this.buildMysqlPageSql(sql, startRow, pageSize);
} else if ("informix".equals(this.getDbType())) {
return this.buildInformixPageSql(sql, startRow, pageSize);
}
throw new DataBaseException("don't support db type,please confirm db is oracle or mysql or informix");
}
private String buildOraclePageSql(String sql, int startRow, int pageSize) {
StringBuilder pageSql = new StringBuilder("SELECT * FROM ");
pageSql.append(" ( ");
pageSql.append(" SELECT pageDataTable.*, ROWNUM RNV ");
pageSql.append(" FROM (" + sql + " ) pageDataTable ");
pageSql.append(" WHERE ROWNUM <= " + (startRow + pageSize));
pageSql.append(" ) WHERE RNV >= " + (startRow + 1));
return pageSql.toString();
}
private String buildMysqlPageSql(String sql, int startRow, int pageSize) {
sql = sql + " limit " + startRow + ", " + pageSize;
return sql;
}
private String buildInformixPageSql(String sql, int startRow, int pageSize) {
sql = sql.trim();
if (sql.startsWith("select")) {
sql = sql.replaceFirst("select", " select skip " + startRow + " first " + pageSize + " ");
} else {
sql = sql.replaceFirst("SELECT", " select skip " + startRow + " first " + pageSize + " ");
}
return sql;
}
private Integer getValidPage(Integer pageNo, int totalRows, Integer pageSize) {
if (!isValidPage(pageNo, totalRows, pageSize)) {
return getValidPage(--pageNo, totalRows, pageSize);
}
int pageCount = (totalRows + (pageSize - (totalRows % pageSize == 0 ? pageSize : totalRows % pageSize)))
/ pageSize;
return pageCount;
}
private static int getStartOfPage(int pageNo, int pageSize) {
if(pageNo==0){
pageNo=1;
}
return (pageNo - 1) * pageSize;
}
private boolean isValidPage(Integer pageNo, Integer totalRows, Integer pageSize) {
if (pageNo == 1) {
return true;
}
int rowStart = (pageNo - 1) * pageSize;
int rowEnd = rowStart + pageSize;
if (rowEnd > totalRows) {
rowEnd = totalRows;
}
return rowEnd > rowStart;
}
/**
* 查詢記錄數
*
* @param sql
* @param columnNameForCount
* @param praValuesMap
* @return
*/
// @SuppressWarnings("deprecation")
public int getResultCountWithValuesMap(String sql, String columnNameForCount, Map<String, Object> praValuesMap) {
if (praValuesMap != null && praValuesMap.isEmpty()) {
praValuesMap = null;
}
String countQuerySql = null;
countQuerySql = " select count(*) from ( " + sql + " ) V_TABLE";
return namedParameterJdbcTemplate.queryForInt(countQuerySql, praValuesMap);
}
public int queryForIntWithpraValuesMap(String countQuerySql, Map<String, Object> praValuesMap) {
if (praValuesMap != null && praValuesMap.isEmpty()) {
praValuesMap = null;
}
return namedParameterJdbcTemplate.queryForInt(countQuerySql, praValuesMap);
}
public int queryForInt(String countQuerySql, Object... args) {
return getJdbcTemplate().queryForInt(countQuerySql, args);
}
public static String getSqlFromQueryData(String sql, Map<String, Object> paramMap) {
if (StringUtils.isEmpty(sql)) {
return null;
}
if (paramMap == null) {
return sql;
}
StringBuffer sqlExp = new StringBuffer(sql);
Set<Entry<String, Object>> set = paramMap.entrySet();
for (Entry<String, Object> entry : set) {
int start = sqlExp.indexOf(":" + entry.getKey() + " ");
if (start < 0) {
continue;
}
int last = sqlExp.lastIndexOf(":" + entry.getKey() + " ");
if (start >= 0 && start == last) {
if (entry.getValue() != null) {
sqlExp.replace(start, start + entry.getKey().length(), "'" + entry.getValue().toString() + "'");
// sqlExp.replace(start-1, start+entry.getKey().length(),
// "'"+entry.getValue().toString()+"'");
}
} else {
// 處理同一參數多處出現
sqlExp.replace(start, start + entry.getKey().length(), "'" + entry.getValue().toString() + "'");
start = sqlExp.indexOf(":" + entry.getKey());
while (start > 0) {
sqlExp.replace(start, start + entry.getKey().length(), "'" + entry.getValue().toString() + "'");
start = sqlExp.indexOf(":" + entry.getKey());
}
}
}
return sqlExp.toString();
}
private static String removeSelect(String sql) {
int beginPos = sql.indexOf(" from ");
if (beginPos < 0) {
beginPos = sql.indexOf("from ");
}
if (beginPos < 0) {
beginPos = sql.toLowerCase().indexOf(" from ");
}
if (beginPos < 0) {
beginPos = sql.toLowerCase().indexOf("from ");
}
return sql.substring(beginPos);
}
/**
* 去除sql的orderby 用于頁查果詢
*
* @param sql
* @return
*/
private static String removeOrders(String sql) {
Pattern p = Pattern.compile("order\\s*by[\\w|\\W|\\s|\\S]*", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(sql);
StringBuffer sb = new StringBuffer();
while (m.find()) {
m.appendReplacement(sb, "");
}
m.appendTail(sb);
return sb.toString();
}
public String getDbType() {
return dbType;
}
public NamedParameterJdbcTemplate getNamedParameterJdbcTemplate() {
return namedParameterJdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
this.namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate);
}
public String getMysqlLowerCaseTableNames() {
return mysqlLowerCaseTableNames;
}
public void setMysqlLowerCaseTableNames(String mysqlLowerCaseTableNames) {
this.mysqlLowerCaseTableNames = mysqlLowerCaseTableNames;
}
public String isShowSql() {
return showSql;
}
public void setShowSql(String showSql) {
this.showSql = showSql;
}
} 三：使用
資料源和JPA是同一資料源，在同一事務中，用的連接配接和JPA使用的是同一個連接配接，在CommonDao 額外注入一個 JdbcTemplateWrapper,當作處理複雜SQL的幫手。
JdbcTemplateWrapper 常用的方法同如下幾個：
clasz 把查詢結果要轉為的類對像，内部再構造 ObjectRowMapper
1：public List queryAllMatchListWithFreePra(String sql, Class clasz,
Object... args) // SQL 參數為問号占位符，使用參數個數<=3
個時的情況,可以用要不參數多了，可變長參數多，閱讀性差
2：public List queryAllMatchListWithParaMap(String sql, Class clasz,
Map paramMap) // SQL 參數，為 參數名占位符 ,如 name=:name, paramMap中 key 為參數名，value
為值數值(用于參數個數多于3時，用參數名占位符的方式，然後用Map 傳參) ; 如clasz 傳為為空，實際返為
List<Map<String,Object>>,不為空側為
List<Map<String,clasz>>
3： 以pageModel為載體實作分頁
/**
*
* @param pageModel: 設定了查詢SQL ，及查詢參數 Map paramMap 的分頁對像
* @param className
* : 從查詢結果集中建構出的類，如為null則pageModel的PageData為List<Map>，
* 不為null則pageModel的PageData為List<className>
* @param columnNameForCount:查詢記錄數時的字段名，一般用主鍵
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public void fillPageModelData(PageModel pageModel, Class className)
4 ： 不用 pageModel 分頁查詢
/**
* 多表sql 分頁查詢,多表連查時，才用這個方法，其他請用commonDao的 SQL分頁查詢
* @param sql
* @param paramMap
* @param pageNo
* @param PageSize
* @param columnNameForCount
* @return
public List queryAllMatchListWithParaMap(String sql, Class clasz, Map paramMap, int pageNo, int pageSize)
5 ： 把list map 原生JDBC結果集中，字段名，也就是MAP中的KEY，轉換為駝峰規則的JAVA對屬性名
* 把list map 原生JDBC結果集中，字段名，也就是MAP中的KEY，轉換為駝峰規則的JAVA對屬性名
* 友善前端元件使用，不再中間轉為VO 或 實體類對像後，再返前端;比傳統查詢（多了一個LIST的周遊 ，基本對性能影響不大）
* @param resultList ：JDBC 結果集
* @return 把MAP中的KEY轉換為轉換為駝峰規則的JAVA對屬性名的LIST<map<駝峰規則的JAVA對屬性名形式的KEY,Object>>
* @author itest andy
public void converDbColumnName2ObjectPropName(List<Map<String,Object>> resultList)
轉自本人在部落格園的原創 ，在這裡還算不算原創?