学习资料1

1.右键项目-》属性-》java bulid path-》jre System Library-》access rules-》resolution选择accessible，下面填上** 点击确定即可！！！

2.

在MyEclipse中编写Java代码时，用到了BASE64Decoder，import sun.misc.BASE64Decoder；可是Eclipse提示：
Access restriction: The type BASE64Decoder is not accessible due to restriction on required library C:\Program
files\java\jre6\lib\rt.jar
Access restriction : The constructor BASE64Decoder() is not accessible due to restriction on required library C:\Program files\java\jre6\lib\rt.jar

解决方案1（推荐）：
只需要在project build path中先移除JRE System Library，再添加库JRE System Library，重新编译后就一切正常了。
解决方案2：
Windows -> Preferences -> Java -> Compiler -> Errors/Warnings ->
Deprecated and trstricted API -> Forbidden reference (access rules): -> change to warning

 

 

2.验证码

http://www.jb51.net/article/42157.htm

 

 

3.调用存储过程

package cn.edu.jdbc;

import java.sql.CallableStatement;
import java.sql.Connection;

import oracle.jdbc.OracleTypes;

import org.junit.Test;
/**
 * create or replace procedure queryempinform(eno in number,
                                           pename out varchar2,
                                           psal out number,
                                           pjob out varchar2)
 * @author wf
 *
 */
public class TestProcedure {
    @Test
    public void testProcedure(){
        //{call <procedure-name[(<arg1>,<arg2>,<arh3>...)]>}
        String sql = "{call queryempincome1(?,?,?,?)}";

        Connection connection = null;
        CallableStatement call = null;
        try {
            //得到一個连接
            connection = JDBCUtils.getConnection();
            //通过连接创建输出statement
            call = connection.prepareCall(sql);

            //对于in(输入)参数，要赋值
            call.setInt(1, 2);//为第一个存储过程的参数赋值为1表示查询编号为1的员工信息

            //对于out(输出)，需要申明
//          call.registerOutParameter(2, sqlType);
            call.registerOutParameter(2, OracleTypes.VARCHAR);//指定oracle的输出参数类型
            call.registerOutParameter(3, OracleTypes.NUMBER);
            call.registerOutParameter(4, OracleTypes.VARCHAR);

            //执行调用
            call.execute();

            //取出结果
            String name = call.getString(2);
            Double sal = call.getDouble(3);
            String job = call.getString(4);
            System.out.println("姓名:"+name+"\t"+"薪水:"+sal+"\t"+"工作:"+job);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
4. tomcat启动错误
 tomcat启动servlet项目  java.lang.illegalstateexception containerBase.addChild
   1.jar冲突  （如jstl.jar）
   2.  tomcat.util.scan.DefaultJarScanner.jarsToSkip=\ 值后面加",*"。

4.  
/*            BufferedReader br = new BufferedReader(new InputStreamReader(                      (ServletInputStream) request.getInputStream(), "utf-8"));              StringBuffer sb = new StringBuffer("");              String temp;              while ((temp = br.readLine()) != null) {                  sb.append(temp);              }              br.close();              String backStr = sb.toString();             JSONObject json=new JSONObject(backStr);            json.getString("");*/
/*            BufferedReader br = new BufferedReader(new InputStreamReader(                      (ServletInputStream) request.getInputStream(), "utf-8"));              StringBuffer sb = new StringBuffer("");              String temp;              while ((temp = br.readLine()) != null) {                  sb.append(temp);              }              br.close();              String backStr = sb.toString();             JSONObject json=new JSONObject(backStr);            json.getString("");*/