欢迎使用CSDN-markdown编辑器

来源：互联网发布：众途软件多少钱编辑：程序博客网时间：2024/06/06 10:04
直接上代码，效果还不错。
import java.io.BufferedReader;import java.io.InputStreamReader;import java.net.URL;import java.net.URLConnection;import java.nio.charset.Charset;/** * @author Crunchify.com */public class CrunchifyRetryNTimes {    public static void main(String[] args) {        // Execute this Program as it is once to get correct response.        // Change URL to        // http://crunchify.com/wp-content/uploads/code/json.sample2.txt to        // see retry logic in action..        String myURL = "http://www.google.om";        CrunchifyRetryOnExceptionStrategy retry = new CrunchifyRetryOnExceptionStrategy();        while (retry.shouldRetry()) {            try {                System.out.println("Requested URL:" + myURL);                StringBuilder sb = new StringBuilder();                URLConnection urlConn = null;                InputStreamReader in = null;                URL url = new URL(myURL);                urlConn = url.openConnection();                if (urlConn != null) urlConn.setReadTimeout(60 * 1000);                if (urlConn != null && urlConn.getInputStream() != null) {                    in = new InputStreamReader(urlConn.getInputStream(), Charset.defaultCharset());                    BufferedReader bufferedReader = new BufferedReader(in);                    if (bufferedReader != null) {                        int cp;                        while ((cp = bufferedReader.read()) != -1) {                            sb.append((char) cp);                        }                        bufferedReader.close();                    }                }                System.out.println(sb.toString());                in.close();                break;            } catch (Exception e) {                try {                    System.out.println("in catch.....");                    retry.errorOccured();                } catch (RuntimeException e1) {                    throw new RuntimeException("Exception while calling URL:" + myURL, e);                } catch (Exception e1) {                    throw new RuntimeException(e1);                }            }        }    }    static class CrunchifyRetryOnExceptionStrategy {        public static final int  DEFAULT_RETRIES            = 3;        public static final long DEFAULT_WAIT_TIME_IN_MILLI = 2000;        private int              numberOfRetries;        private int              numberOfTriesLeft;        private long             timeToWait;        public CrunchifyRetryOnExceptionStrategy() {            this(DEFAULT_RETRIES, DEFAULT_WAIT_TIME_IN_MILLI);        }        public CrunchifyRetryOnExceptionStrategy(int numberOfRetries, long timeToWait) {            this.numberOfRetries = numberOfRetries;            numberOfTriesLeft = numberOfRetries;            this.timeToWait = timeToWait;        }        /**         * @return true if there are tries left         */        public boolean shouldRetry() {            return numberOfTriesLeft > 0;        }        public void errorOccured() throws Exception {            numberOfTriesLeft--;            if (!shouldRetry()) {                throw new Exception("Retry Failed: Total " + numberOfRetries + " attempts made at interval "                                    + getTimeToWait() + "ms");            }            waitUntilNextTry();        }        public long getTimeToWait() {            return timeToWait;        }        private void waitUntilNextTry() {            try {                Thread.sleep(getTimeToWait());            } catch (InterruptedException ignored) {            }        }    }}
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