Java Swing组件JFileChooser用法实例分析

本文实例讲述了java swing组件jfilechooser用法。分享给大家供大家参考，具体如下：

jfilechooser文件选择器是swing中经常用到的一个控件。它的使用主要包含以下几个参数：

1.当前路径。也就是它第一次打开时所在的路径，许多软件喜欢设置为桌面。

2.文件过滤器。通过设置文件过滤器，只有特定类型的文件是可见的，比如文本，音频，等。

3.选择模式。包含三种情况：仅文件, 仅目录, 文件或目录。

4.是否允许多选。

jfilechooser的参数当然不止以上4种，它还有很多高级选项，比如你可以对文件的显示图标进行定制等，由于不经常用，这里不再介绍。

有2个地方要注意：

1.文件过滤器建议使用filenameextensionfilter，它是filefilter的子类，以非常方便的方法实现了过滤器。用法见代码。

2.getselectedfiles()方法，它只在ismultiselectionenable()方法返回true是有效。也就是说，如果你不允许多选，则只能使用getselectedfile()方法，否则只能得到一个空的文件列表。

下面通过一个demo来展示它的基本用法。

package awtdemo;
import java.io.file;
import javax.swing.jfilechooser;
import javax.swing.joptionpane;
import javax.swing.filechooser.filenameextensionfilter;
import javax.swing.filechooser.filesystemview;
/**
 *
 * @author pzy
 */
@suppresswarnings("serial")
public class jfilechooserframe extends javax.swing.jframe {
  /**
   * creates new form jfilechooserframe
   */
  public jfilechooserframe() {
    initcomponents();
  }
  /**
   * this method is called from within the constructor to initialize the form.
   * warning: do not modify this code. the content of this method is always
   * regenerated by the form editor.
   */
  @suppresswarnings({ "unchecked", "rawtypes" })
  // <editor-fold defaultstate="collapsed" desc="generated code">
  private void initcomponents() {
    filefilterisbg = new javax.swing.buttongroup();
    ismultiselectbg = new javax.swing.buttongroup();
    jpanel1 = new javax.swing.jpanel();
    text_rb = new javax.swing.jradiobutton();
    video_rb = new javax.swing.jradiobutton();
    audio_rb = new javax.swing.jradiobutton();
    all_rb = new javax.swing.jradiobutton();
    jpanel2 = new javax.swing.jpanel();
    jcombobox1 = new javax.swing.jcombobox();
    multiselect_rb = new javax.swing.jradiobutton();
    singleselect_rb = new javax.swing.jradiobutton();
    jpanel3 = new javax.swing.jpanel();
    jbutton1 = new javax.swing.jbutton();
    setdefaultcloseoperation(javax.swing.windowconstants.exit_on_close);
    setlocationbyplatform(true);
    jpanel1.setborder(javax.swing.borderfactory.createtitledborder("文件类型"));
    filefilterisbg.add(text_rb);
    text_rb.settext("文本");
    filefilterisbg.add(video_rb);
    video_rb.settext("视频");
    filefilterisbg.add(audio_rb);
    audio_rb.settext("音频");
    filefilterisbg.add(all_rb);
    all_rb.setselected(true);
    all_rb.settext("所有");
    javax.swing.grouplayout jpanel1layout = new javax.swing.grouplayout(jpanel1);
    jpanel1.setlayout(jpanel1layout);
    jpanel1layout.sethorizontalgroup(
      jpanel1layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(javax.swing.grouplayout.alignment.trailing, jpanel1layout.createsequentialgroup()
        .addcontainergap(javax.swing.grouplayout.default_size, short.max_value)
        .addcomponent(text_rb)
        .addgap(29, 29, 29)
        .addcomponent(video_rb)
        .addgap(35, 35, 35)
        .addcomponent(audio_rb)
        .addgap(39, 39, 39)
        .addcomponent(all_rb)
        .addgap(32, 32, 32))
    );
    jpanel1layout.setverticalgroup(
      jpanel1layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(jpanel1layout.createsequentialgroup()
        .addcontainergap()
        .addgroup(jpanel1layout.createparallelgroup(javax.swing.grouplayout.alignment.baseline)
          .addcomponent(video_rb)
          .addcomponent(text_rb)
          .addcomponent(audio_rb)
          .addcomponent(all_rb))
        .addcontainergap(javax.swing.grouplayout.default_size, short.max_value))
    );
    jpanel2.setborder(javax.swing.borderfactory.createtitledborder("选择模式"));
    jcombobox1.setmodel(new javax.swing.defaultcomboboxmodel(new string[] { "仅文件", "仅目录", "文件或目录" }));
    jcombobox1.addactionlistener(new java.awt.event.actionlistener() {
      public void actionperformed(java.awt.event.actionevent evt) {
        jcombobox1actionperformed(evt);
      }
    });
    ismultiselectbg.add(multiselect_rb);
    multiselect_rb.settext("可多选");
    ismultiselectbg.add(singleselect_rb);
    singleselect_rb.setselected(true);
    singleselect_rb.settext("不可多选");
    javax.swing.grouplayout jpanel2layout = new javax.swing.grouplayout(jpanel2);
    jpanel2.setlayout(jpanel2layout);
    jpanel2layout.sethorizontalgroup(
      jpanel2layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(jpanel2layout.createsequentialgroup()
        .addcontainergap()
        .addcomponent(jcombobox1, javax.swing.grouplayout.preferred_size, 144, javax.swing.grouplayout.preferred_size)
        .addgap(18, 18, 18)
        .addcomponent(multiselect_rb, javax.swing.grouplayout.preferred_size, 82, javax.swing.grouplayout.preferred_size)
        .addgap(18, 18, 18)
        .addcomponent(singleselect_rb, javax.swing.grouplayout.preferred_size, 82, javax.swing.grouplayout.preferred_size)
        .addcontainergap(14, short.max_value))
    );
    jpanel2layout.setverticalgroup(
      jpanel2layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(jpanel2layout.createsequentialgroup()
        .addcontainergap()
        .addgroup(jpanel2layout.createparallelgroup(javax.swing.grouplayout.alignment.baseline)
          .addcomponent(jcombobox1, javax.swing.grouplayout.preferred_size, javax.swing.grouplayout.default_size, javax.swing.grouplayout.preferred_size)
          .addcomponent(multiselect_rb)
          .addcomponent(singleselect_rb))
        .addcontainergap(16, short.max_value))
    );
    jbutton1.settext("开始");
    jbutton1.addactionlistener(new java.awt.event.actionlistener() {
      public void actionperformed(java.awt.event.actionevent evt) {
        jbutton1actionperformed(evt);
      }
    });
    javax.swing.grouplayout jpanel3layout = new javax.swing.grouplayout(jpanel3);
    jpanel3.setlayout(jpanel3layout);
    jpanel3layout.sethorizontalgroup(
      jpanel3layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(jpanel3layout.createsequentialgroup()
        .addgap(117, 117, 117)
        .addcomponent(jbutton1, javax.swing.grouplayout.preferred_size, 139, javax.swing.grouplayout.preferred_size)
        .addcontainergap(javax.swing.grouplayout.default_size, short.max_value))
    );
    jpanel3layout.setverticalgroup(
      jpanel3layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(jpanel3layout.createsequentialgroup()
        .addgap(26, 26, 26)
        .addcomponent(jbutton1, javax.swing.grouplayout.preferred_size, 32, javax.swing.grouplayout.preferred_size)
        .addcontainergap(19, short.max_value))
    );
    javax.swing.grouplayout layout = new javax.swing.grouplayout(getcontentpane());
    getcontentpane().setlayout(layout);
    layout.sethorizontalgroup(
      layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(layout.createsequentialgroup()
        .addcontainergap()
        .addgroup(layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
          .addcomponent(jpanel1, javax.swing.grouplayout.default_size, javax.swing.grouplayout.default_size, short.max_value)
          .addcomponent(jpanel2, javax.swing.grouplayout.default_size, javax.swing.grouplayout.default_size, short.max_value)
          .addgroup(layout.createsequentialgroup()
            .addcomponent(jpanel3, javax.swing.grouplayout.default_size, javax.swing.grouplayout.default_size, short.max_value)
            .addgap(84, 84, 84)))
        .addcontainergap())
    );
    layout.setverticalgroup(
      layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)
      .addgroup(layout.createsequentialgroup()
        .addgap(8, 8, 8)
        .addcomponent(jpanel1, javax.swing.grouplayout.preferred_size, javax.swing.grouplayout.default_size, javax.swing.grouplayout.preferred_size)
        .addgap(18, 18, 18)
        .addcomponent(jpanel2, javax.swing.grouplayout.preferred_size, javax.swing.grouplayout.default_size, javax.swing.grouplayout.preferred_size)
        .addgap(18, 18, 18)
        .addcomponent(jpanel3, javax.swing.grouplayout.preferred_size, javax.swing.grouplayout.default_size, javax.swing.grouplayout.preferred_size)
        .addcontainergap(javax.swing.grouplayout.default_size, short.max_value))
    );
    pack();
  }// </editor-fold>
  private void jcombobox1actionperformed(java.awt.event.actionevent evt) {
    // todo add your handling code here:
    string itemstring = jcombobox1.getselecteditem().tostring();
    if ("仅文件".equals(itemstring)) {
      fileselectionmode = jfilechooser.files_only;
    } else if ("仅目录".equals(itemstring)) {
      fileselectionmode = jfilechooser.directories_only;
    } else if ("文件或目录".equals(itemstring)) {
      fileselectionmode = jfilechooser.files_and_directories;
    }
  }
  private void jbutton1actionperformed(java.awt.event.actionevent evt) {
    // todo add your handling code here:
    filechooser = new jfilechooser();
    //初始化当前路径
    filesystemview fsv = filesystemview.getfilesystemview();
    file homefile =fsv.gethomedirectory();  //这便是读取桌面路径的方法了
    filechooser.setcurrentdirectory(homefile);
    //初始化文件过滤器
    if (text_rb.isselected()) {
      filter = new filenameextensionfilter("文本文件", "log", "txt");
      filechooser.setfilefilter(filter);
    }
    if (video_rb.isselected()) {
      filter = new filenameextensionfilter("视频文件", "mp4", "mkv");
      filechooser.setfilefilter(filter);
    }
    if (audio_rb.isselected()) {
      filter = new filenameextensionfilter("音频文件", "mp3", "wma");
      filechooser.setfilefilter(filter);
    }
    //初始化选择模式
    filechooser.setfileselectionmode(fileselectionmode);
    //是否允许多选
    if (multiselect_rb.isselected()) {
      filechooser.setmultiselectionenabled(true);
    }
    else if(singleselect_rb.isselected()) {
      filechooser.setmultiselectionenabled(false);
    }
    //打开文件选择器
    int i = filechooser.showdialog(this, "选择");
    if(i == jfilechooser.approve_option){
      stringbuilder sb;
      if(filechooser.ismultiselectionenabled()){
      sb = new stringbuilder("您选择了以下文件：");
      file [] files = filechooser.getselectedfiles();
      for (file file : files) {
        sb.append("\n");
        sb.append(file.getname());
      }
      }
      else{
        file file = filechooser.getselectedfile();
        sb = new stringbuilder("您选择的文件是：");
         sb.append("\n");
        sb.append(file.getname());
      }
      joptionpane.showmessagedialog(this, sb);
    }
  }
  /**
   * @param args the command line arguments
   */
  public static void main(string args[]) {
    /* set the nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" look and feel setting code (optional) ">
    /* if nimbus (introduced in java se 6) is not available, stay with the default look and feel.
     * for details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
     */
    try {
      for (javax.swing.uimanager.lookandfeelinfo info : javax.swing.uimanager.getinstalledlookandfeels()) {
        if ("nimbus".equals(info.getname())) {
          javax.swing.uimanager.setlookandfeel(info.getclassname());
          break;
        }
      }
    } catch (classnotfoundexception ex) {
      java.util.logging.logger.getlogger(jfilechooserframe.class.getname()).log(java.util.logging.level.severe, null, ex);
    } catch (instantiationexception ex) {
      java.util.logging.logger.getlogger(jfilechooserframe.class.getname()).log(java.util.logging.level.severe, null, ex);
    } catch (illegalaccessexception ex) {
      java.util.logging.logger.getlogger(jfilechooserframe.class.getname()).log(java.util.logging.level.severe, null, ex);
    } catch (javax.swing.unsupportedlookandfeelexception ex) {
      java.util.logging.logger.getlogger(jfilechooserframe.class.getname()).log(java.util.logging.level.severe, null, ex);
    }
    //</editor-fold>
    /* create and display the form */
    java.awt.eventqueue.invokelater(new runnable() {
      public void run() {
        new jfilechooserframe().setvisible(true);
      }
    });
  }
  private jfilechooser filechooser;
  private filenameextensionfilter filter;
  private int fileselectionmode = jfilechooser.files_only;
  // variables declaration - do not modify
  private javax.swing.jradiobutton all_rb;
  private javax.swing.jradiobutton audio_rb;
  private javax.swing.buttongroup filefilterisbg;
  private javax.swing.buttongroup ismultiselectbg;
  private javax.swing.jbutton jbutton1;
  @suppresswarnings("rawtypes")
 private javax.swing.jcombobox jcombobox1;
  private javax.swing.jpanel jpanel1;
  private javax.swing.jpanel jpanel2;
  private javax.swing.jpanel jpanel3;
  private javax.swing.jradiobutton multiselect_rb;
  private javax.swing.jradiobutton singleselect_rb;
  private javax.swing.jradiobutton text_rb;
  private javax.swing.jradiobutton video_rb;
  // end of variables declaration
}

运行效果如下：

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