//1
package package1;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
import org.apache.commons.dbcp.BasicDataSource;
public class DBUtil {
private static BasicDataSource ds;
static{
Properties p = new Properties();
try {
p.load(DBUtil.class.getClassLoader().getResourceAsStream("db.perproties"));
String driver = p.getProperty("driver");
String url = p.getProperty("url");
String user = p.getProperty("user");
String pwd = p.getProperty("pwd");
String initsize = p.getProperty("initsize");
String maxsize = p.getProperty("maxsize");
ds = new BasicDataSource();
ds.setDriverClassName(driver);
ds.setUrl(url);
ds.setUsername(user);
ds.setPassword(pwd);
ds.setInitialSize(new Integer(initsize));
ds.setMaxActive(new Integer(maxsize));
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("读取配置文件异常",e);
}
}
public static Connection getConnection() throws SQLException{
return ds.getConnection();
}
public static void closeConnection(Connection conn){
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("关闭连接异常",e);
}
}
}
public static void rollBack(Connection conn){
if(conn!=null){
try {
conn.rollback();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("回滚操作异常",e);
}
}
}
}
//2
driver=oracle.jdbc.driver.OracleDriver
url=jdbc:oracle:thin:@localhost:1521:orcl
user=SYSTEM
pwd=MINg4978
initsize=1
maxsize=3
//3
/**
* 根据ID查看一个员工
/
public Emp findById(int id) {
Connection conn = null;
Emp e = null;
try {
conn = DBUtil.getConnection();
System.out.println("连接池创建成功");
String sql = "select * from emp where empno = ?";
System.out.println(11);
PreparedStatement ps = conn.prepareStatement(sql);
System.out.println(22);
ps.setInt(1, id);
System.out.println(33);
ResultSet rs = ps.executeQuery();
System.out.println(44);
if (rs.next()) {
e = createEmp(rs);
return e;
}
} catch (Exception e1) {
e1.printStackTrace();
throw new RuntimeException("查询员工异常", e1);
} finally {
DBUtil.closeConnection(conn);
}
return null;
}
/*
控制台输出结果是这样的:
连接池创建成功
11
22
33
java.sql.SQLException: ORA-00942: 表或视图不存在
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:745)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
at oracle.jdbc.driver.T4CPreparedStatement.executeForDescribe(T4CPreparedStatement.java:810)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1039)
at oracle.jdbc.driver.T4CPreparedStatement.executeMaybeDescribe(T4CPreparedStatement.java:850)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1134)
at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3339)
at oracle.jdbc.driver.OraclePreparedStatement.executeQuery(OraclePreparedStatement.java:3384)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
at packageEmp.EmpDao.findById(EmpDao.java:85)
at TestPackage.Test01.main(Test01.java:9)
Exception in thread "main" java.lang.RuntimeException: 查询员工异常
at packageEmp.EmpDao.findById(EmpDao.java:93)
at TestPackage.Test01.main(Test01.java:9)
Caused by: java.sql.SQLException: ORA-00942: 表或视图不存在
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:745)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
at oracle.jdbc.driver.T4CPreparedStatement.executeForDescribe(T4CPreparedStatement.java:810)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1039)
at oracle.jdbc.driver.T4CPreparedStatement.executeMaybeDescribe(T4CPreparedStatement.java:850)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1134)
at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3339)
at oracle.jdbc.driver.OraclePreparedStatement.executeQuery(OraclePreparedStatement.java:3384)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
at packageEmp.EmpDao.findById(EmpDao.java:85)
... 1 more