发布于 2016-07-05 00:13:38 | 183 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Java设计模式，程序狗速度看过来！

Java程序设计语言

java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言，是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台（即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se)）的总称。

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java 下执行mysql 批量插入的几种方法及用时,1000次插入方法的比较。

方法1：

Java code

conn = DriverManager.getConnection(JDBC_URL, JDBC_USER, JDBC_PASS);
        pstmt = conn
                .prepareStatement("insert into loadtest (id, data) values (?, ?)");
        for (int i = 1; i <= COUNT; i++) {
            pstmt.clearParameters();
            pstmt.setInt(1, i);
            pstmt.setString(2, DATA);
            pstmt.execute();
        }

MyISAM：246.6秒、InnoDB：360.2秒

方法2： 使用事务，不自动commit

Java code

conn = DriverManager.getConnection(JDBC_URL, JDBC_USER, JDBC_PASS);
        conn.setAutoCommit(false);
        pstmt = conn
                .prepareStatement("insert into loadtest (id, data) values (?, ?)");
        for (int i = 1; i <= COUNT; i++) {
            pstmt.clearParameters();
            pstmt.setInt(1, i);
            pstmt.setString(2, DATA);
            pstmt.execute();
            if (i % COMMIT_SIZE == 0) {
                conn.commit();
            }
        }
        conn.commit();

InnoDB：31.5秒

方法3： executeBatch

Java code

conn = DriverManager.getConnection(JDBC_URL
                + "?rewriteBatchedStatements=true", JDBC_USER, JDBC_PASS);
        conn.setAutoCommit(false);
        pstmt = conn
                .prepareStatement("insert into loadtest (id, data) values (?, ?)");
        for (int i = 1; i <= COUNT; i += BATCH_SIZE) {
            pstmt.clearBatch();
            for (int j = 0; j < BATCH_SIZE; j++) {
                pstmt.setInt(1, i + j);
                pstmt.setString(2, DATA);
                pstmt.addBatch();
            }
            pstmt.executeBatch();
            if ((i + BATCH_SIZE - 1) % COMMIT_SIZE == 0) {
                conn.commit();
            }
        }
        conn.commit();

InnoDB：5.2秒

上面的使用时必须
1）rewriteBatchedStatements=true
2）useServerPrepStmts=true

方法4：先LOAD再COMMIT

Java code

conn = DriverManager.getConnection(JDBC_URL, JDBC_USER, JDBC_PASS);
        conn.setAutoCommit(false);
        pstmt = conn.prepareStatement("load data local infile '' "
                + "into table loadtest fields terminated by ','");
        StringBuilder sb = new StringBuilder();
        for (int i = 1; i <= COUNT; i++) {
            sb.append(i + "," + DATA + "\n");
            if (i % COMMIT_SIZE == 0) {
                InputStream is = new ByteArrayInputStream(sb.toString()
                        .getBytes());
                ((com.mysql.jdbc.Statement) pstmt)
                        .setLocalInfileInputStream(is);
                pstmt.execute();
                conn.commit();
                sb.setLength(0);
            }
        }
        InputStream is = new ByteArrayInputStream(sb.toString().getBytes());
        ((com.mysql.jdbc.Statement) pstmt).setLocalInfileInputStream(is);
        pstmt.execute();
        conn.commit();