uploadimage.java

jsp 应用开发技术光盘 是《jsp应用开发技术》这本书的源代码

package ch14.binaryFile;

import java.sql.*;
import java.io.*;
import java.nio.*;
import ch14.datasource.*;

public class UploadImage {
	public boolean storeImage(String sqlstr, File file) {
		try {
			//打开文件
			FileInputStream fin = new FileInputStream(file);
			//建一个缓冲保存数据
			ByteBuffer nbf = ByteBuffer.allocate((int) file.length());
			byte[] array = new byte[1024];
			int offset = 0, length = 0;
			//读存数据
			while ((length = fin.read(array)) > 0) {
				if (length != 1024)
					nbf.put(array, 0, length);
				else
					nbf.put(array);
				offset += length;
			}
			//关闭文件
			fin.close();
			//新建一个数组保存要写的内容
			byte[] content = nbf.array();
			//保存数据
			return setImage(sqlstr, content);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		//如果发生文件读写错误都会返回false
		return false;
	}

	private boolean setImage(String sqlstr, byte[] in) {
		boolean flag = false;
		if (sqlstr == null)
			sqlstr = "select * from picture_table";
		try {
			Connection conn = SqlTestDS.getConnection();
			Statement stmt =
				conn.createStatement(
					ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.CONCUR_UPDATABLE);
			ResultSet rs = stmt.executeQuery(sqlstr);
			if (rs.next()) {
				rs.updateBytes(2, in);
				rs.updateRow();
			} else {
				rs.moveToInsertRow();
				rs.updateString(1, "01");
				rs.updateBytes(2, in);
				rs.insertRow();
			}
			rs.close();
			flag = true;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return flag;
	}

	//测试
	public static void main(String[] args) {
		UploadImage upload = new UploadImage();
		try {

			File file = new File("01.jpg");
			if (upload.storeImage(null, file))
				System.out.println("true");
			else
				System.out.println("false");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}