Question

请教java更新mysql，更新进程sleep

请教java批量更新mysql，为什么update进程会sleep呢？？？那个数据库只有我一个人在用的，只执行一个select，然后依次根据id进行update,有时候update进程就sleep了.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.concurrent.ArrayBlockingQueue;

public class DBwriteThread implements Runnable {
private volatile ArrayBlockingQueue<Documents> queue2;
private volatile ArrayBlockingQueue<Integer> flag;

public DBwriteThread(ArrayBlockingQueue<Documents> queue2,
ArrayBlockingQueue<Integer> flag) {
this.queue2 = queue2;
this.flag = flag;
}

public void run() {
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/dev";
String user = "user";
String password = "password";
Connection conn = null;
PreparedStatement stmt = null;
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
conn.setAutoCommit(false);
while ((flag.size() < 2) || (!(queue2.isEmpty()))) {
try {
String sql = "update SINA_LEARN_SAMPLE set PARSE_LINE=?,WORD=?,TIMES=?,FEATURE=? where document_id=";
Documents newDocument = queue2.take();
String sql1 = sql + (newDocument.getDocumentID());
String word;
String times;
String feature;
stmt = conn.prepareStatement(sql1);
word = ArrayListToString(newDocument.getWord());
times = ArrayListToString(newDocument.getTime());
feature = ArrayListToString(newDocument.getFeature());
stmt.setString(1, newDocument.getParseLine().get(0));
stmt.setString(2, word);
stmt.setString(3, times);
stmt.setString(4, feature);
stmt.executeUpdate();
conn.commit();
} catch (InterruptedException e1) {
break;
}
}
flag.put(5);
} catch (ClassNotFoundException e1) {
System.err.println("装载JDBC失败");
e1.printStackTrace();
} catch (SQLException e2) {
System.err.println("SQL异常");
e2.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}

public String ArrayListToString(ArrayList<String> newArray) {
String result = null;
for (int i = 0; i < newArray.size(); i++) {
if (result == null) {
result = newArray.get(i);
} else {
result = result + "," + newArray.get(i);
}
}
return result;
}
}

Answer 1

你本机CPU 如果被别的进程占用 你的jVM会sleep

Answer 2

你的main函数拿出来晒晒

Answer 3

我感觉广州疯狂JAVA不错 你对JAVA感兴趣可以去学他们的课程 和看疯狂JAVA书籍

Answer 4

用进程是会有莫名其妙问题，有时候昨天好的今天就有问题，明天又好了