Java实现图片裁剪预览功能
时间:2020-04-01
本文章向大家介绍Java实现图片裁剪预览功能，主要包括Java实现图片裁剪预览功能使用实例、应用技巧、基本知识点总结和需要注意事项，具有一定的参考价值，需要的朋友可以参考一下。
在项目中，我们需要做些类似头像上传，图片裁剪的功能，ok看下面文章！
需要插件：jQuery Jcrop
后端代码：
package org.csg.upload;
import java.awt.Rectangle;
import java.awt.p_w_picpath.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Iterator;
import javax.p_w_picpathio.ImageIO;
import javax.p_w_picpathio.ImageReadParam;
import javax.p_w_picpathio.ImageReader;
import javax.p_w_picpathio.stream.ImageInputStream;
public class Upload {
/**
* @author 小夜的传说
* @param path1 图片原路径
* @param path2 裁剪后存储的路径
* @param x x轴
* @param y y轴
* @param w
* @param h
*/
public static void CutImage(String path1,String path2,int x,int y,int w,int h){
FileInputStream fileInputStream=null;
ImageInputStream iis=null;
try {
//读取图片文件，建立文件输入流
fileInputStream=new FileInputStream(path1);
//创建图片的文件流 迭代器
Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName("jpg");
ImageReader reader=it.next();
//获取图片流 建立文图 文件流
iis=ImageIO.createImageInputStream(fileInputStream);
//获取图片默认参数
reader.setInput(iis, true);
ImageReadParam param=reader.getDefaultReadParam();
//定义裁剪区域
Rectangle rect=new Rectangle(x,y,w,h);
param.setSourceRegion(rect);
BufferedImage bi=reader.read(0,param);
ImageIO.write(bi, "jpg", new File(path2));
} catch (Exception e) {
e.printStackTrace();
System.out.println("裁剪失败");
}finally{
try {
if(fileInputStream!=null){
fileInputStream.close();
}
if(iis!=null){
iis.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}访问代码：
<%@ page language="java" import="java.util.*,org.csg.upload.*" pageEncoding="utf-8"%>
<%
//图片的相对路径
String imagPath=request.getParameter("imgPath");
String relPath=request.getRealPath("/");//获取图片服务器绝对地址
String newFileName=new Date().getTime()+".jpg";
//实际图片路径
String path1=relPath+imagPath;
//裁剪后存储到服务器的图片路径
String path2=relPath+"/p_w_picpaths/"+newFileName;
int x=Integer.parseInt(request.getParameter("x"));
int y=Integer.parseInt(request.getParameter("y"));
int w=Integer.parseInt(request.getParameter("w"));
int h=Integer.parseInt(request.getParameter("h"));
try{
Upload.CutImage(path1, path2, x, y, w, h);
out.print("<img src='p_w_picpaths/"+newFileName+"'/>");
}catch(Exception e){
e.printStackTrace();
out.print("图片裁剪失败");
}
%>
jsp代码：
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Jsp开发头像裁剪</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<link rel="stylesheet" href="css/jquery.Jcrop.css" type="text/css" />
<script type="text/javascript" src="js/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.Jcrop.min.js"></script>
<style type="text/css">
*{margin: 0;padding: 0;}
.cut{
margin-top: 20px;
}
#preview-pane {
display: block;
position: absolute;
z-index: 2000;
top: 10px;
right: -280px;
padding: 6px;
border: 1px rgba(0,0,0,.4) solid;
background-color: white;
-webkit-border-radius: 6px;
-moz-border-radius: 6px;
border-radius: 6px;
-webkit-box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2);
-moz-box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2);
box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2);
}
#preview-pane .preview-container {
width: 250px;
height: 170px;
overflow: hidden;
}
</style>
<script