[Apache commons系列]DBUtils简介
。
DbUtils是一个小型的类库，这里通过具体实例来说明如何使用DbUtils。示例分为3个类：DbUtilsExample演示了如何使用DbUtils 类；QueryRunnerExample 演示了如何使用QueryRunner 、ResultSetHandler ；User 类为一个JavaBean，对应于数据库中的表格。示例采用MySQL为数据库，使用JDBC4.0驱动（最大的区别就是不需要写Class.forName().newInstance() ）。sh）
* commons-dbcp-1.2.2.jar：提供数据库连接池
* commons-dbutils-1.3.jar：DbUtils包
* commons-lang-2.4.jar：提供常用的工具方法
* commons-pool-1.5.3.jar：提供DBCP对象池化机制
* mysql-connector-java-5.1.10-bin.jar：MySQL JDBC4.0驱动
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DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`USERNAME` varchar(30) NOT NULL,
`PASSWORDHASH` varchar(256),
PRIMARY KEY (`USERNAME`),
KEY `USERNAME` (`USERNAME`)
);
DROP TABLE IF EXISTS `user`; CREATE TABLE `user` ( `USERNAME` varchar(30) NOT NULL, `PASSWORDHASH` varchar(256), PRIMARY KEY (`USERNAME`), KEY `USERNAME` (`USERNAME`) );
DbUtilsExample.java ：
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import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.commons.dbutils.DbUtils;
public class DbUtilsExample {
public static void main(String[] args) {
String url = "jdbc:mysql://127.0.0.1:3306/test";
String user = "test";
String password = "test";
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
stmt
.executeUpdate("INSERT INTO user (USERNAME, PASSWORDHASH) values ('testUser', '123456')");
DbUtils.closeQuietly(stmt);
DbUtils.commitAndCloseQuietly(conn);
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
DbUtils.rollbackAndCloseQuietly(conn);
}
PreparedStatement psmt = null;
try {
conn = DriverManager.getConnection(url, user, password);
psmt = conn.prepareStatement("SELECT USERNAME, PASSWORDHASH FROM user");
rs = psmt.executeQuery();
while (rs.next()) {
System.out.println(rs.getString(1) + "\t" + rs.getString(2));
}
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
} finally {
DbUtils.closeQuietly(conn, psmt, rs);
}
try {
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
stmt.executeUpdate("DELETE FROM user WHERE USERNAME='testUser'");
DbUtils.closeQuietly(stmt);
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
} finally {
DbUtils.printWarnings(conn);
DbUtils.closeQuietly(conn);
}
}
}
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.commons.dbutils.DbUtils;
public class DbUtilsExample {
public static void main(Stringa[] args) {
String url = "jdbc:mysql://127.0.0.1:3306/test";
String user = "test";
String password = "test";
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
stmt
.executeUpdate("INSERT INTO user (USERNAME, PASSWORDHASH) values ('testUser', '123456')");
DbUtils.closeQuietly(stmt);
DbUtils.commitAndCloseQuietly(conn);
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
DbUtils.rollbackAndCloseQuietly(conn);
}
PreparedStatement psmt = null;
try {
conn = DriverManager.getConnection(url, user, password);
psmt = conn.prepareStatement("SELECT USERNAME, PASSWORDHASH FROM user");
rs = psmt.executeQuery();
while (rs.next()) {
System.out.println(rs.getString(1) + "\t" + rs.getString(2));
}
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
} finally {
DbUtils.closeQuietly(conn, psmt, rs);
}
try {
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
stmt.executeUpdate("DELETE FROM user WHERE USERNAME='testUser'");
DbUtils.closeQuietly(stmt);
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
} finally {
DbUtils.printWarnings(conn);
DbUtils.closeQuietly(conn);
}
}
}
QueryRunnerExample.java ：
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import static java.lang.System.out;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ArrayHandler;
import org.apache.commons.dbutils.handlers.ArrayListHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ColumnListHandler;
import org.apache.commons.dbutils.handlers.KeyedHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.apache.commons.lang.StringUtils;
public class QueryRunnerExample {
public static void main(String[] args) throws SQLException {
QueryRunnerExample example = new QueryRunnerExample();
example.batch();
example.fillStatement();
example.query();
example.update();
example.closeDataSource();
}
private DataSource dataSource = null;
private QueryRunner runner = null;
public QueryRunnerExample() {
initDataSource();
runner = new QueryRunner(dataSource);
}
private void batch() {
String sql = "INSERT INTO user (USERNAME, PASSWORDHASH) values (?, ?)";
try {
out.println("\n" + StringUtils.center("Test QueryRunner batch", 80, '*'));
int[] result = runner.batch(sql, new Object[][] { { "user1", "pwd1" },
{ "user2", "pwd2" }, { "user3", "pwd3" }, { "user4", "pwd4" } });
out.printf("运行结果：%s\n", Arrays.toString(result));
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
}
}
private void closeDataSource() throws SQLException {
((BasicDataSource) dataSource).close();
}
private void fillStatement() throws SQLException {
String sql = "INSERT INTO user (USERNAME, PASSWORDHASH) VALUES (?, ?)";
Connection conn = null;
try {
out.println("\n" + StringUtils.center("Test QueryRunner fillStatement", 80, '*'));
conn = dataSource.getConnection();
PreparedStatement psmt = conn.prepareStatement(sql);
runner.fillStatementWithBean(psmt, new User("testUser5", "pwd5"), "userName",
"passwordHash");
out.println(psmt.executeUpdate());
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
} finally {
DbUtils.commitAndCloseQuietly(conn);
}
}
private DataSource initDataSource() {
if (dataSource == null) {
BasicDataSource basicDs = new BasicDataSource();
basicDs.setUrl("jdbc:mysql://127.0.0.1:3306/test");
basicDs.setUsername("test");
basicDs.setPassword("test");
this.dataSource = basicDs;
}
return dataSource;
}
private void query() throws SQLException {
out.println("\n" + StringUtils.center("Test QueryRunner query", 80, '*'));
String sql = "SELECT * FROM user WHERE USERNAME LIKE ?";
out.println("1.Test QueryRunner query, ArrayHandler");
//把ResultSet第一行包装成Object[]
Object[] r1 = runner.query(sql, new ArrayHandler(), "user%");
out.println(" " + Arrays.deepToString(r1));
out.println("2.Test QueryRunner query, ArrayListHandler");
//把ResultSet包装成List<Object[]>
List<Object[]> r2 = runner.query(sql, new ArrayListHandler(), "user%");
out.println(" " + Arrays.deepToString(r2.toArray()));
out.println("3.Test QueryRunner query, BeanHandler");
//把ResultSet第一行包装成一个JavaBean
User r3 = runner.query(sql, new BeanHandler<User>(User.class), "user%");
out.println(" " + r3.toString());
out.println("4.Test QueryRunner query, BeanListHandler");
//把ResultSet第一行包装成一个List<JavaBean>；
List<User> r4 = runner.query(sql, new BeanListHandler<User>(User.class), "user%");
out.println(" " + Arrays.deepToString(r4.toArray()));
out.println("5.Test query, ColumnListHandler");
//抽取ResultSet指定的列，以List<Object>对象的形式返回，默认第一列
List<Object> r5 = runner.query(sql, new ColumnListHandler(2), "user%");
out.println(" " + Arrays.deepToString(r5.toArray()));
out.println("6.Test QueryRunner query, KeyedHandler");
//包装ResultSet，以Map<Object,Map<String,Object>>对象形式返回，第一个Object是指定的列值，第二个Map中String是列名且对大小写不敏感
Map<Object, Map<String, Object>> r6 = runner.query(sql, new KeyedHandler(2), "user%");
out.println(" " + r6.toString());
out.println("7.Test QueryRunner query, MapHandler");
//把ResultSet第一行包装成Map<String, Object>，key对大小写不敏感
Map<String, Object> r7 = runner.query(sql, new MapHandler(), "user%");
out.println(" " + r7.toString());
out.println("8.Test QueryRunner query, MapListHandler");
//把ResultSet包装成List<Map<String,Object>>>，Map的key对大小写不敏感
List<Map<String, Object>> r8 = runner.query(sql, new MapListHandler(), "user%");
out.println(" " + r8.toString());
out.println("9.Test QueryRunner query, ScalarHandler");
//抽取ResultSet第一行指定列，以Object对象形式返回
Object r9 = runner.query(sql, new ScalarHandler("passwordhash"), "user%");
out.println(" " + r9.toString());
}
private void update() {
String sql = "DELETE FROM user WHERE PASSWORDHASH LIKE ?";
try {
out.println("\n" + StringUtils.center("Test QueryRunner update", 80, '*'));
out.println(runner.update(sql, "pwd%"));
} catch (SQLException ex) {
DbUtils.printStackTrace(ex);
}
}
}[Apache commons系列]DBUtils简介-inkfish原创
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