标签:c style class blog code java
需要拷贝连接Oracle的jar包,路径如下图所示:
连接Oracle数据库的代码:
package demo.utils;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCUtils {
private static String driver = "oracle.jdbc.OracleDriver";
private static String url = "jdbc:oracle:thin:@192.168.56.101:1521:orcl";
private static String user = "scott";
private static String password = "tiger";
static{
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
throw new ExceptionInInitializerError(e);
}
}
public static Connection getConnection(){
try {
return DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
/*
* 运行Java程序
* java -Xms100M -Xmx200M HellWorld
*
* 技术方向:
* 1. 性能调优
* 2. 故障诊断: 死锁
*/
public static void release(Connection conn,Statement st,ResultSet rs){
if(rs != null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
rs = null;//why? --> Java GC,让Java的垃圾回收器回收,我们是不能控制垃圾回收器的,即使我们调用了System.gc(),也是不能立即回收的,Java的垃圾回收器是不可控的。
}
}
if(st != null){
try {
st.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
st = null;
}
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
conn = null;
}
}
}
}
Java GC,让Java的垃圾回收器回收,我们是不能控制垃圾回收器的,即使我们调用了System.gc(),也是不能立即回收的,Java的垃圾回收器是不可控的。System.gc()只是请求jvm回收。
测试的代码:
分别是在Java语言中调用存储过程、在Java语言中调用存储函数、在Java语言中调用包头和包体。
--查询某个员工的姓名 职位和月薪
/*
思考:
1. out参数太多???
2. 查询某个部门中所有员工的所有信息
*/
create or replace procedure queryEmpInfoma(eno in number,
pename out varchar2,
pjob out varchar2,
psal out number)
as
begin
select ename,empjob,sal into pename,pjob,psal from emp where empno=eno;
end;
/
--查询某个员工的年收入
create or replace function queryEmpIncome(eno in number)
return number
as
--定义变量保存月薪和奖金
psal emp.sal%type;
pcomm emp.comm%type;
begin
select sal,comm into psal,pcomm from emp where empno=eno;
--返回年收入
return psal*12+nvl(pcomm,0);
end;
/
declare
income number;
begin
income:=queryEmpIncome(7369);
dbms_output.put_line(income);
end;
/
查询某个部门中所有员工的所有信息
包头
CREATE OR REPLACE PACKAGE MYPACKAGE AS
type empcursor is ref cursor;
procedure queryEmpList(dno in number,empList out empcursor);
END MYPACKAGE;
包体
CREATE OR REPLACE PACKAGE BODY MYPACKAGE AS
procedure queryEmpList(dno in number,empList out empcursor) AS
BEGIN
open empList for select * from emp where deptno=dno;
END queryEmpList;
END MYPACKAGE;
package demo.oracle;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleTypes;
import org.junit.Test;
import demo.utils.JDBCUtils;
/*
* 思考
* 1. 光标close了吗?关闭了,光标是通过call得到的,而call是通过conn得到的,所以conn关闭了,那么光标就关闭了
* 2. 下面的代码能在mysql上运行吗?不能,实际和理论总是有差别的。
*/
public class TestOracle {
/*
* create or replace procedure queryEmpInfo(eno in number,
pename out varchar2,
pjob out varchar2,
psal out number)
*/
@Test
public void tesProcedure(){
// {call <procedure-name>[(<arg1>,<arg2>, ...)]}
String sql = "{call queryEmpInfoma(?,?,?,?)}";
Connection conn = null;
CallableStatement call = null;
try {
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql);
//对于in参数,赋值
call.setInt(1, 7839);
//对于out参数,申明
call.registerOutParameter(2, OracleTypes.VARCHAR);
call.registerOutParameter(3, OracleTypes.VARCHAR);
call.registerOutParameter(4, OracleTypes.NUMBER);
//执行
call.execute();
//取出结果
String name = call.getString(2);
String job = call.getString(3);
double sal = call.getDouble(4);
System.out.println(name);
System.out.println(job);
System.out.println(sal);
} catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, null);
}
}
/*
* create or replace function queryEmpIncome(eno in number)
return number
*/
@Test
public void tesFunction(){
//{?= call <procedure-name>[(<arg1>,<arg2>, ...)]}
String sql = "{?=call queryEmpIncome(?)}";
Connection conn = null;
CallableStatement call = null;
try {
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql);
//对于out参数,申明
call.registerOutParameter(1, OracleTypes.NUMBER);
//对于in参数,赋值
call.setInt(2, 7839);
//执行
call.execute();
//取出结果
double income = call.getDouble(1);
System.out.println(income);
} catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, null);
}
}
@Test
public void testCursor(){
String sql = "{call MYPACKAGE.queryEmpList(?,?)}";
Connection conn = null;
CallableStatement call = null;
ResultSet rs = null;
try {
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql);
//对于in参数,赋值
call.setInt(1,20);
//对于out参数,申明
call.registerOutParameter(2, OracleTypes.CURSOR);
//执行
call.execute();
//取出结果
rs = ((OracleCallableStatement)call).getCursor(2);
while(rs.next()){
String name = rs.getString("ename");
String job = rs.getString("job");
double sal = rs.getDouble("sal");
System.out.println(name+"\t"+job+"\t"+sal);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, rs);
}
}
}在Java语言中调用存储过程、存储函数、包头、包体,布布扣,bubuko.com
标签:c style class blog code java
原文地址:http://blog.csdn.net/tangliuqing/article/details/27875237