Java Swing 多线程加载图片（保证顺序一致）_Java教程

大二的时候做的课程设计，图片管理器，当时遇到图片很多的文件夹，加载顺序非常慢。虽然尝试用多个thread加载图片，却无法保证图片按顺序加载。直到今天学会了使用callable接口和future接口，于是心血来潮实现了这个功能。

废话不多说，看代码。

多线程加载图片（核心）：

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									package com.lin.imagemgr;

									import java.awt.dimension;

									import java.awt.image.bufferedimage;

									import java.io.file;

									import java.io.filenamefilter;

									import java.io.ioexception;

									import java.util.arraylist;

									import java.util.list;

									import java.util.concurrent.executionexception;

									import java.util.concurrent.executorservice;

									import java.util.concurrent.executors;

									import java.util.concurrent.future;

									import java.util.stream.collectors;

									import javax.swing.imageicon;

									import javax.swing.jlabel;

									import net.coobird.thumbnailator.thumbnails;

									public class imagemgr {

									 private static imagemgr instance = new imagemgr();

									 private imagemgr() {}

									 public static imagemgr getinstance() {

									  return instance;

									 }

									 //线程池

									 private executorservice executor = executors.newfixedthreadpool(8);

									 public list<jlabel> loadimages(string path) {

									  list<jlabel> images = new arraylist<>();

									  file file = new file(path);

									  if (!file.isdirectory()) {

									   throw new runtimeexception("need directory!");

									  }

									  file[] files = file.listfiles(new filenamefilter() {

									   @override

									   public boolean accept(file dir, string name) {

									    //thumbnail只支持jpg??

									    if (name.endswith(".jpg")) {

									     return true;

									    }

									    return false;

									   }

									  });

									  //并发加载图片，并使用future保存加载结果

									  list<future<mylabel>> futures = new arraylist<>();

									  for (final file f : files) {

									   future<mylabel> future = executor.submit(() -> {

									    return new mylabel(f.getname(), f.getabsolutepath());

									   });

									   futures.add(future);

									  }

									  //等待所有并发加载返回结果

									  try {

									   for (future<mylabel> future : futures) {

									    mylabel icon = future.get();

									    images.add(icon);

									   }

									  } catch (interruptedexception e) {

									   e.printstacktrace();

									  } catch (executionexception e) {

									   e.printstacktrace();

									  }

									  //java8使用stream api 进行排序

									  list<jlabel> sortedlist = images.stream().sorted().collect(collectors.tolist());

									  return sortedlist;

									 }

									 //继承jlabel并实现comparable接口，从而对jlabel进行排序

									 private static class mylabel extends jlabel implements comparable<mylabel>{

									  private static final long serialversionuid = 1l;

									  private string filename;

									  public mylabel(string filename, string fullpath) {

									   this.filename = filename;

									   //使用thumbnailator生成缩略图

									   try {

									    bufferedimage bufferedimage = thumbnails.of(fullpath) 

									    .size(100, 120)

									    .asbufferedimage();

									    seticon(new imageicon(bufferedimage));

									    setpreferredsize(new dimension(100, 120));

									   } catch (ioexception e) {

									    e.printstacktrace();

									   }

									  }

									  @override

									  public int compareto(mylabel o) {

									   int result = this.filename.compareto(o.filename);

									   return result;

									  }

									 }

									}

swing界面：

									package com.lin.imagemgr;

									import java.awt.borderlayout;

									import java.awt.dimension;

									import java.awt.flowlayout;

									import java.util.list;

									import javax.swing.jbutton;

									import javax.swing.jframe;

									import javax.swing.jlabel;

									import javax.swing.jpanel;

									import javax.swing.jscrollpane;

									import javax.swing.jtextfield;

									public class mainframe extends jframe{

									 private static final long serialversionuid = 1l;

									 private jtextfield pathfield;

									 private jbutton showbtn;

									 private jpanel contentpanel;

									 public void init() {

									  jpanel toppanel = new jpanel(new flowlayout(flowlayout.left, 5, 0));

									  toppanel.setpreferredsize(new dimension(800, 40));

									  pathfield = new jtextfield(50);

									  showbtn = new jbutton("显示图片");

									  toppanel.add(pathfield);

									  toppanel.add(showbtn);

									  getcontentpane().add(borderlayout.north, toppanel);

									  contentpanel = new jpanel();

									  contentpanel.setlayout(new flowlayout(flowlayout.left, 5, 5));

									  contentpanel.setpreferredsize(new dimension(750, 1800));

									  jscrollpane jsp = new jscrollpane(contentpanel);

									  getcontentpane().add(borderlayout.center, jsp);

									  showbtn.addactionlistener((e) -> {

									   try {

									    loadimages();

									   } catch (exception ex) {

									    ex.printstacktrace();

									   }

									  });

									  setsize(800, 650);

									  setdefaultcloseoperation(jframe.exit_on_close);

									  setlocationrelativeto(null);

									  setvisible(true);

									 }

									 public void loadimages() {

									  contentpanel.removeall();

									  string path = pathfield.gettext();

									  long start = system.currenttimemillis();

									  list<jlabel> images = imagemgr.getinstance().loadimages(path);

									  for (jlabel label :images) {

									   contentpanel.add(label);

									  }

									  contentpanel.updateui();

									  long end = system.currenttimemillis();

									  system.out.println("加载需要" + (end - start) + "毫秒！");

									 }

									 public static void main(string[] args) {

									  new mainframe().init();

									 }

									}