基本的JDBC以及CRUD/Transaction基本操作

        <!-- mysql start -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <!-- mysql end -->
        <!-- junit start -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!-- junit end -->
        <!-- log start -->
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.7</version>
        </dependency>
        <!-- log end -->

/**
 * JDBCUtil with mysql-connector-java-5.1.38.jar<br>
 * 
 * @author Changjiang.Chen
 *
 */
public class JDBCUtil {

    private static final Log log = LogFactory.getLog(JDBCUtil.class);
    private static String URL;
    private static String USER;
    private static String PASS;
    private static String DRIVER;
    static {
        InputStream is = JDBCUtil.class.getClassLoader().getResourceAsStream("mysql.properties");
        Properties prop = new Properties();
        try {
            prop.load(is);
            URL = prop.getProperty("url");
            USER = prop.getProperty("user");
            PASS = prop.getProperty("password");
            DRIVER = prop.getProperty("driver");
            Class.forName(DRIVER);
        } catch (IOException e) {
            log.error("sth wrong with the property file loading pro", e);
        } catch (ClassNotFoundException e) {
            log.error("JDBCUtil:Class.forName(" + DRIVER + ") error", e);
        }
    }

    /**
     * 建立链接
     * 
     * @return
     */
    public static Connection getConnection() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(URL, USER, PASS);
        } catch (SQLException e) {
            log.error("JDBCUtil:getConnection() error", e);
        }
        return conn;
    }

    /**
     * 关闭资源
     * 
     * @param conn
     * @param st
     * @param rs
     */
    public static void closeMysqlResouces(Connection conn, Statement st, ResultSet rs) {
        try {
            if (rs != null) {
                rs.close();
            }
        } catch (Exception e) {
            log.error("JDBCUtil:rs.close() error", e);
        } finally {
            try {
                if (st != null) {
                    st.close();
                }
            } catch (Exception e2) {
                log.error("JDBCUtil:st.close() error", e2);
            } finally {
                try {
                    if (conn != null) {
                        conn.close();
                    }
                } catch (Exception e3) {
                    log.error("JDBCUtil:conn.close() error", e3);
                }
            }
        }
    }

}

public class TestJDBCUtil {
    @Test
    public void testGetConn() {
        Object obj = JDBCUtil.getConnection();
        Assert.assertNotNull(obj);
    }

}

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Arrays;

import org.junit.Assert;
import org.junit.FixMethodOrder;
import org.junit.Test;
import org.junit.runners.MethodSorters;

/**
 * @author Changjiang.Chen
 */
/**
 * 重新组合所有测试的执行顺序，按照字母表排序进行执行
 */
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class TestCRUD {
    private Connection conn;
    private Statement st;
    private ResultSet rs;
    private PreparedStatement pst;

    @Test
    public void testAInsert() {
        try {
            conn = JDBCUtil.getConnection();
            st = conn.createStatement();
            String sql = "INSERT INTO content(id,type,info,num,validtime,label) VALUES(7,‘测试‘,‘测试信息‘,0,10,‘chiq3_test‘)";
            int r = st.executeUpdate(sql);
            JDBCUtil.closeMysqlResouces(conn, st, null);
            Assert.assertEquals(1, r);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtil.closeMysqlResouces(conn, st, null);
        }
    }

    /**
     * 参数传入方式可能引起SQL注入
     * 
     * @throws SQLException
     */
    @Test
    public void testCQuery1() throws SQLException {
        try {
            conn = JDBCUtil.getConnection();
            st = conn.createStatement();
            /**
             * param may be affected
             */
            String injectParam = "1";
            String sql = "select type from content where id = " + injectParam;
            rs = st.executeQuery(sql);
            String type = "";
            if (rs.next()) {
                type = rs.getString("type");
            }
            Assert.assertEquals("追剧推送", type);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtil.closeMysqlResouces(conn, st, rs);
        }
    }

    /**
     * preparedStatement对比Statement<br>
     * 如果可以保证sql语句不包含调用者传入的参数，可用后者，否则用前者<br>
     * 大部分情况下都倾向于使用前者，DBUtil,Hibernate都采用了pst
     * 
     * @throws SQLException
     */
    @Test
    public void testCQuery2() throws SQLException {
        try {
            conn = JDBCUtil.getConnection();
            /**
             * param could not be affected
             */
            String injectParam = "1";
            String sql = "select type from content where id = ?";
            pst = conn.prepareStatement(sql);
            pst.setString(1, injectParam);
            rs = pst.executeQuery();
            String type = "";
            if (rs.next()) {
                type = rs.getString("type");
            }
            Assert.assertEquals("追剧推送", type);
        } catch (Exception e) {
            e.printStackTrace(); // TODO: handle exception
        } finally {
            JDBCUtil.closeMysqlResouces(conn, pst, rs);
        }
    }

    /**
     * pst应用场景<br>
     * 1.放置sql注入 <br>
     * 2.大数据处理:用IO流处理参数 <br>
     * 3.批处理
     * 
     * @throws SQLException
     */
    @Test
    public void testCUpdate() throws SQLException {
        try {
            conn = JDBCUtil.getConnection();
            String injectParam = "7";
            String sql = "UPDATE content SET type = ‘TEST_PUSH‘ WHERE id = ?";
            pst = conn.prepareStatement(sql);
            pst.setString(1, injectParam);
            int r = pst.executeUpdate();
            Assert.assertEquals(1, r);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtil.closeMysqlResouces(conn, pst, rs);
        }
    }

    /**
     * 批量操作
     * 
     * @throws SQLException
     */
    @Test
    public void testYBatchUpdate() throws SQLException {
        try {

            conn = JDBCUtil.getConnection();
            String sql = "INSERT INTO content(id,type,info,num,validtime,label) VALUES(?,?,?,?,?,?)";
            pst = conn.prepareStatement(sql);
            for (int i = 10; i < 30; i++) {
                pst.setInt(1, i);
                pst.setString(2, "测试推送");
                pst.setString(3, "测试信息");
                pst.setInt(4, i);
                pst.setInt(5, 10);
                pst.setString(6, "开启测试推送模式");
                pst.addBatch();
            }
            int[] r = pst.executeBatch();
            int[] expected = new int[20];
            for (int i = 0; i < expected.length; i++) {
                expected[i] = 1;
            }
            Assert.assertEquals(Arrays.toString(expected), Arrays.toString(r));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtil.closeMysqlResouces(conn, pst, null);
        }
    }

    /**
     * Transaction
     */
    @Test
    public void testZTransaction() {
        conn = JDBCUtil.getConnection();
        try {
            conn.setAutoCommit(false);
            st = conn.createStatement();
            int r1 = st.executeUpdate("delete from content where id = 7");
            int r2 = st.executeUpdate("DELETE FROM content WHERE validtime = 10");
            conn.commit();
            Assert.assertEquals(Arrays.toString(new int[] { r1, r2 }), Arrays.toString(new int[] { 1, 20 }));
        } catch (SQLException e) {
            e.printStackTrace();
            try {
                conn.rollback();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
        } finally {
            JDBCUtil.closeMysqlResouces(conn, st, null);
        }
    }

}