使用Java合并图片、修改DPI详解编程语言

package com.snow.web.a_test; 
import java.awt.Graphics; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import javax.imageio.ImageIO; 
import com.sun.image.codec.jpeg.JPEGCodec; 
import com.sun.image.codec.jpeg.JPEGEncodeParam; 
import com.sun.image.codec.jpeg.JPEGImageEncoder; 
public class Test { 
private static String path = "F://"; 
public static void main(String[] args) throws Exception { 
System.out.println("======================================="); 
//        String path = "F://test.jpg";   
//      File files = new File(path);   
//      handleDpi(files, 300, 300);  
//        String path = "F://";   
File file1 = new File(path, "1.jpg");   
File file2 = new File(path, "2.png");   
//        mosaicImage(file1, file2);  
        mergeImage(file1, file2);  
} 
/**  
* 改变图片DPI  
*  
* @param file  
* @param xDensity  
* @param yDensity  
* @throws ImageReadException  
*/   
public static void handleDpi(File file, int xDensity, int yDensity){   
try {   
BufferedImage image = ImageIO.read(file);   
JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(new FileOutputStream(file));   
JPEGEncodeParam jpegEncodeParam = jpegEncoder.getDefaultJPEGEncodeParam(image);   
jpegEncodeParam.setDensityUnit(JPEGEncodeParam.DENSITY_UNIT_DOTS_INCH);   
jpegEncoder.setJPEGEncodeParam(jpegEncodeParam);   
jpegEncodeParam.setQuality(0.75f, false);   
jpegEncodeParam.setXDensity(xDensity);   
jpegEncodeParam.setYDensity(yDensity);   
jpegEncoder.encode(image, jpegEncodeParam);   
image.flush();   
} catch (IOException e) {   
e.printStackTrace();   
}   
}  
/** 
* 图片拼接 
* @param file1 左边 
* @param file2    右边 
* @throws IOException 
*/ 
public static void mosaicImage(File file1, File file2) throws IOException {         
BufferedImage image1 = ImageIO.read(file1);   
BufferedImage image2 = ImageIO.read(file2);   
BufferedImage combined = new BufferedImage(image1.getWidth() * 2, image1.getHeight(), BufferedImage.TYPE_INT_RGB);   
// paint both images, preserving the alpha channels   
Graphics g = combined.getGraphics();   
g.drawImage(image1, 0, 0, null);   
g.drawImage(image2, image1.getWidth(), 0, null);   
// Save as new image   
ImageIO.write(combined, "JPG", new File(path, "3.jpg"));   
}   
/** 
* 图片合并 
* @param file1 左边 
* @param file2    右边 
* @throws IOException 
*/ 
public static void mergeImage(File file1, File file2) throws IOException {         
BufferedImage image1 = ImageIO.read(file1);   
BufferedImage image2 = ImageIO.read(file2);   
BufferedImage combined = new BufferedImage(image1.getWidth(), image1.getHeight(), BufferedImage.TYPE_INT_RGB);   
// paint both images, preserving the alpha channels   
Graphics g = combined.getGraphics();   
System.out.println(image2.getData()); 
g.drawImage(image1, 0, 0, null);   
g.drawImage(image2, 0, 0, image1.getWidth(), image1.getHeight(), null);   
// Save as new image   
ImageIO.write(combined, "JPG", new File(path, "4.jpg"));   
}   
}