java读取json文件为list，并进行rest传输

java读取json文件为list，并进行rest传输（单纯的为自己记录代码，免得要用的时候找不到）

读取json文件（两个方法）

1. 从工程里读取json文件

String dir = request.getSession().getServletContext().getRealPath("/resource/文件名.json");
           

1. 从本地读取json文件

String dir = "C:\\Users\\Desktop\\文件名.json";
           

文件处理成List（借助com.alibaba.fastjson.JSONObject）

fastjson 版本用的是1.2.20 低版本有些情况会报错（具体哪一版修复的不太清楚）

List<Map<String,Object>> maps = new ArrayList<>();
	try {
			//转换为文件
            File file = new File(dir);
            if (!file.exists()) {
                file.createNewFile();
            }
            //把读入的文件转换为字符，以便json去处理
            String str= FileUtils.readFileToString(file, "UTF-8");
            //借助阿里的fastJson处理
            maps = (List)JSONObject.parseArray(str,Map.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
           

起线程池发起rest请求

起线程池：

ThreadPoolExecutor executor = new ThreadPoolExecutor(5, 10, 200, TimeUnit.MILLISECONDS,
                new ArrayBlockingQueue<Runnable>(5));
           

发送请求：

省略for循环遍历maps的过程

final String mapStr = JSONObject.toJSONString(maps.get(i));
	executor.execute(new Runnable() {
                @Override
                public void run() {
                    HttpClient httpClient = new HttpClient();
                    PostMethod method = new PostMethod("rest访问地址");
                    try{
                        RequestEntity requestEntity = new StringRequestEntity(mapStr, "application/json", "utf-8");
                        method.setRequestEntity(requestEntity);
                        //状态返回码
                        int statusCode = httpClient.executeMethod(method);
                        //下面是捕获返回的response值
                        if (statusCode == 200) {
	                        StringBuilder sb = new StringBuilder();
	                        InputStream ins = method.getResponseBodyAsStream();
	                        BufferedReader reader = new BufferedReader(new InputStreamReader(ins,"UTF-8"));
	                        String line = " ";
	                        while ((line = reader.readLine()) != null){
	                            sb.append(line);
	                        }
	                        System.out.println(sb.toString());
	                        //或者用字节读
	                        //InputStream ins = null;
                            //StringBuilder sb = new StringBuilder();
                            //ins = method.getResponseBodyAsStream();
                            //byte[] b = new byte[1024];
                            //int r_len = 0;
                            //while ((r_len = ins.read(b)) > 0) {
                               // sb.append(new String(b, 0, r_len, method.getResponseCharSet()));
                            //}
                            //System.out.println(sb.toString());
                        }
                        
                    }catch (Exception e){
                        System.out.println("212121");
                        e.printStackTrace();
                    }
                }
            });
           

json例子

[{"id":11,"jsonrpc":"2.0","params":{"id":1}},
{"id":22,"jsonrpc":"2.0","params":{"id":2}},
{"id":33,"jsonrpc":"2.0","params":{"id":3}},
{"id":44,"jsonrpc":"2.0","params":{"id":4}}]