一、CallableStatement接口的引入

CallableStatement主要是调用数据库中的存储过程，CallableStatement也是Statement接口的子接口。在使用CallableStatement时可以接收存储过程的返回值。

二、使用CallableStatement接口调用存储过程

void registerOutParameter(int parameterIndex,int sqlType)

核心代码：

数据库存储过程：

代码：

public class DbUtil {
	
	//数据库地址
	private static String dbUrl="jdbc:mysql://localhost:3306/db_book";
	//用户名
	private static String dbUserName="root";
	//密码
	private static String dbPassword="root";
	//驱动名称
	private static String jdbcName="com.mysql.jdbc.Driver";
	
	/**
	 * 获取数据库连接
	 * 	1.加载数据库驱动
	 *  2.获取数据库连接
	 */
	public Connection getCon() throws Exception {
		
		Class.forName(jdbcName);//加载数据库驱动
		
		Connection con = DriverManager.getConnection(dbUrl, dbUserName, dbPassword);
		
		return con;
	}
	
	/**
	 * 关闭连接
	 */
	public void close(Statement stmt,Connection con) throws Exception {
		if(stmt!=null) {
			stmt.close();
		}
		if(con!=null) {
			con.close();
		}
	}
}

package com.java1234.jdbc.model;

import java.io.File;

public class Book {
	private int id;
	private String bookName;
	private float price;
	private String author;
	private int bookTypeId;
	private File context;
	private File pic;
	

	public Book(String bookName, float price, String author, int bookTypeId, File context, File pic) {
		super();
		this.bookName = bookName;
		this.price = price;
		this.author = author;
		this.bookTypeId = bookTypeId;
		this.context = context;
		this.pic = pic;
	}

	public Book(String bookName, float price, String author, int bookTypeId, File context) {
		super();
		this.bookName = bookName;
		this.price = price;
		this.author = author;
		this.bookTypeId = bookTypeId;
		this.context = context;
	}

	public Book(String bookName, float price, String author, int bookTypeId) {
		super();
		this.bookName = bookName;
		this.price = price;
		this.author = author;
		this.bookTypeId = bookTypeId;
	}
	
	public Book(int id, String bookName, float price, String author, int bookTypeId) {
		super();
		this.id = id;
		this.bookName = bookName;
		this.price = price;
		this.author = author;
		this.bookTypeId = bookTypeId;
	}

}

demo

public class Demo1 {
	
	private static DbUtil dbUtil = new DbUtil();
	/**
	 * 调用存储过程，通过id查询bookName
	 * @param id
	 * @return
	 * @throws Exception
	 */
	private static String getBookNameById(int id) throws Exception{
		Connection con = dbUtil.getCon();
		String sql = "{CALL pro_getBookNameById(?,?)}";
		CallableStatement cstmt = con.prepareCall(sql);
		cstmt.setInt(1, id);//设置第一个参数
		cstmt.registerOutParameter(2, Types.VARCHAR);//设置返回类型
		cstmt.execute();
		String bookName = cstmt.getString("bn");//获取返回值
		dbUtil.close(cstmt, con);
		return bookName;
	}
	public static void main(String[] args) throws Exception{
		System.out.println("图书名称时："+getBookNameById(4));
	}
	
}