java 重试机制总结

一、try-catch

public class MyTest {
    public static void main(String [] args) {
        try{
            testRedo();
        } catch (Exception e) {
            testRedo();
            e.printStackTrace();
        }
    }

    private static void testRedo() {
        System.out.println("执行Redo代码");
        throw new RuntimeException();
    }

}
           

二、do-while（包括变种：while、递归）

public class MyTest {
    public static void main(String [] args) {
        int maxRetryTime = ;
        int time = ;
        String result = null;
        do {
            time++;
            try {
                result = testRedo();
            } catch (Exception e) {
                e.printStackTrace();
            }
        } while (null == result && time < maxRetryTime);
    }

    private static String testRedo() {
        System.out.println("执行Redo代码");
        // 操作成功，返回结果，操作失败返回null
        return null;
    }
}
           

三、spring-retry

import org.springframework.retry.RecoveryCallback;
import org.springframework.retry.RetryCallback;
import org.springframework.retry.RetryContext;
import org.springframework.retry.policy.SimpleRetryPolicy;
import org.springframework.retry.support.RetryTemplate;

public class MyTest {
    public static void main(String [] args) {
        final String params = "传入参数,可为任意类型，final修饰即可";
        // 重试机制
        RetryTemplate oRetryTemplate = new RetryTemplate();
        SimpleRetryPolicy oRetryPolicy = new SimpleRetryPolicy();
        oRetryPolicy.setMaxAttempts();// 重试5次
        oRetryTemplate.setRetryPolicy(oRetryPolicy);
        try {
            // obj为doWithRetry的返回结果，可以为任意类型
            Object obj = oRetryTemplate.execute(new RetryCallback<Object, Exception>() {
                @Override
                public Object doWithRetry(RetryContext context) throws Exception {// 开始重试
                    System.out.println(params);
                    testRedo();
                    return "此处可返回操作结果";
                }
            }, new RecoveryCallback<Object>() {
                @Override
                public Object recover(RetryContext context) throws Exception { // 重试多次后都失败了
                    return null;
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void testRedo() {
        System.out.println("执行Redo代码");
        throw new RuntimeException();
    }
}
           

需要spring jar包：spring-retry-1.2.0.RELEASE.jar 任意版本