JavaFX的webview下载文件的一种实现思路

灰太狼 2023-03-13 05:59 6阅读 0赞

首先网上找不到webview的下载的demo，资料也很少，毕竟java不擅长桌面客户端所以资料比较少，所以这里就自己找了一下思路，实现了一下，有需要的可以参考一下；  
或者推荐另外一个内嵌浏览器jbrowers，听说不错，不过要付费的，可以找破解版；

内嵌webview效果图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70]  
webview下载图片：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 1]  
webview下载的存放目录：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 2]

首先遇到的几个问题：  
安全 ID 结构无效。![在这里插入图片描述][20200511223123529.png]  
解决：这个是WpSystem这个目录是系统目录，所以报错了，自己新建个目录就可以了；

拒绝访问：  
![在这里插入图片描述][20200511223330923.png]  
解决：这个问题一般是目录有问题或者语法调用有问题

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 3]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 4]

简单的代码demo，不是最优的写法（存在很大优化空间），只是一个思路，具体优化就看自己的；

```java
    package com.javafx;
    
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.util.Collection;
    import java.util.List;
    import java.util.Map;
    import java.util.ResourceBundle;
    import java.util.concurrent.Executor;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    
    import javafx.beans.value.ChangeListener;
    import javafx.beans.value.ObservableValue;
    import javafx.concurrent.Worker;
    import javafx.concurrent.Worker.State;
    import javafx.fxml.FXML;
    import javafx.fxml.Initializable;
    import javafx.scene.web.PopupFeatures;
    import javafx.scene.web.WebEngine;
    import javafx.scene.web.WebEvent;
    import javafx.scene.web.WebView;
    import javafx.util.Callback;
    
    public class Controller implements Initializable { 
    
    	Executor excutor=Executors.newFixedThreadPool(3);
    	private boolean maybeCheckNeedDownLoad = false;
    
    	@FXML
    	private WebView webView;
    
    	@Override
    	public void initialize(URL location, ResourceBundle resources) { 
    		// TODO Auto-generated method stub
    
    		final WebEngine webengine = webView.getEngine();
    		// String url =
    		// Main.class.getResource("/html/index.html").toExternalForm();
    		webengine.getLoadWorker().stateProperty()
    				.addListener(new ChangeListener<State>() { 
    					@Override
    					public void changed(ObservableValue ov, State oldState,
    							State newState) { 
    					
    						if (newState == Worker.State.SUCCEEDED) { 
    							System.out.println("SUCCEEDED");
    							System.out.println(webengine.getLocation());
    						} else if (newState == Worker.State.SCHEDULED) { 
    							System.out.println("SCHEDULED");
    							System.out.println(webengine.getLocation());
    							if (maybeCheckNeedDownLoad)
    								check(webengine.getLocation());
    						} else if (newState == Worker.State.CANCELLED) { 
    							System.out.println("CANCELLED");
    							System.out.println(webengine.getLocation());
    						}
    
    					}
    				});
    		
    		webengine
    				.setOnAlert((WebEvent<String> wEvent) -> { 
    					System.out.println("Alert Event - Message: "
    							+ wEvent.getData());
    				});
    
    		webengine.setOnVisibilityChanged((WebEvent<Boolean> wEvent) -> { 
    			System.out.println("Alert Event - Message: "
    					+ wEvent.getData());
    		});
    		webengine.setOnError((wEvent) -> { 
    			System.out.println("Alert Event - Message: "
    					+ wEvent.getMessage()+"=="+wEvent.getException().toString());
    		});
    		webengine.setOnStatusChanged((WebEvent<String> wEvent) -> { /* System.out.println(wEvent.getSource());
    			 System.out.println(wEvent.getData());
    			 System.out.println(wEvent.getEventType());*/
    			 
    		});
    		webengine
    				.setCreatePopupHandler(new Callback<PopupFeatures, WebEngine>() { 
    					@Override
    					public WebEngine call(PopupFeatures config) { 
    						// do something
    						// return a web engine for the new browser window
    
    						String url = webengine.getLocation();
    						System.out.println("PopupFeatures" + url);
    						maybeCheckNeedDownLoad = true;
    						return webengine;
    					}
    				});
    
    		//webengine.load("http://xiazai.zol.com.cn/down.php?softid=428055&subcateid=1443&site=10&checkStr=b59ee0b66cc7aae39&pos=dxgs2&rand=78ae0");
    		 webengine.load("http://baidu.com/");
    		 //webengine.load("http://local.dg.console.com:8081");
    	
    		// webengine.load("http://local.dg.console.com:8081/api/export/exportStoreList?paramStr=%7B%22pageIndex%22:0,%22pageSize%22:0,%22conditions%22:%5B%7B%22type%22:%22simple%22,%22field%22:%22t.status%22,%22comparison%22:%22Eq%22,%22value%22:%22%22%7D,%7B%22type%22:%22keyword%22,%22field%22:%22t.store_name,t.boss_name%22,%22comparison%22:%22Like%22,%22value%22:%22%22%7D,%7B%22field%22:%22t.create_time%22,%22dateRange%22:%22UNLIMITED%22,%22type%22:%22dateRange%22,%22startDate%22:%22%22,%22endDate%22:%22%22%7D,%7B%22type%22:%22simple%22,%22field%22:%22t.state%22,%22comparison%22:%22Eq%22,%22value%22:%22%22%7D,%7B%22type%22:%22keyword%22,%22field%22:%22t.invite_phone%22,%22comparison%22:%22Like%22,%22value%22:%22%22%7D%5D,%22orders%22:%5B%7B%22field%22:%22t.create_time%22,%22direction%22:%22Desc%22%7D%5D,%22areaCode%22:%22%22,%22areaLevel%22:%22%22,%22paging%22:false%7D");
    	}
    
    	private void check(String url) { 
    		maybeCheckNeedDownLoad = false;
    		System.out.println(url);
    		URL urlobj;
    
    		try { 
    			urlobj = new URL(url);
    			HttpURLConnection urlconnection;
    			urlconnection = (HttpURLConnection) urlobj.openConnection();
    			urlconnection.setRequestMethod("GET");
    			urlconnection.connect();
    			Map headers = urlconnection.getHeaderFields();
    			Object connect_content = headers.get("Content-Disposition");
    			if (connect_content == null) { 
    				connect_content = headers.get("content-disposition");
    			}
    			if (connect_content instanceof Collection) { 
    				List<String> aa = (List<String>) connect_content;
    				String bb = aa.get(0);
    				System.out.println(bb);
    				if (bb.contains("attachment;")) { 
    					excutor.execute(()->{ 
    						String kv[] = bb.split("filename=");
    						String filename= kv[kv.length - 1].replaceAll("\"","");
    						System.out.println("需要下载:" +filename);
    						saveFile(url,"E:\\test\\"+filename);
    					});
    					
    				}
    			}
    
    		} catch (Exception e1) { 
    			// TODO Auto-generated catch block
    			e1.printStackTrace();
    		}
    		return;
    	}
    
    	private void saveFile(String url,String saveFilePathTarget) { 
    		URL uurl;
    		try { 
    			uurl = new URL(url);
    			HttpURLConnection urlconnection=(HttpURLConnection) uurl.openConnection();
    			urlconnection.setRequestMethod("GET");//或者POST
    			File saveFile=new File(saveFilePathTarget);
    			urlconnection.connect();
    			if(!saveFile.exists()){ 
    				System.out.println("不存在");
    				//saveFile.mkdirs();
    			}
    			
    			InputStream inputstream=urlconnection.getInputStream();
    		
    			OutputStream out = new FileOutputStream(saveFile);
                int size = 0;
                int len = 0;
                byte[] buf = new byte[1024];
                while ((size = inputstream.read(buf)) != -1) { 
                    len += size;
                    out.write(buf, 0, size);
               
                }
                inputstream.close();
                out.close();
    		} catch (Exception e) { 
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    			
    			
    	}
    }

总结：
    1、这里因为是demo代码只要是提一下实现思路，实现功能为主，其他的优化自己优化：
    a、webview的弹出窗口事件的监听；
    b、webview判断url的类型是否是下载文件的响应；
    c、是的话就下载；
    目前测试的代码是<a >标签的点击实现的下载，不支持window.open("下载url")的js事件；目前没去找原因是不是不识别window.open（）方法，如果有知道的或者直接如何解决window.open（）的可以通知一下本人，本人记录一下实现方案；

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 1]: /images/20230312/6cb7990f722e4becb1c2a64d5ac36883.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNjg3MTIz_size_16_color_FFFFFF_t_70 2]: /images/20230312/dbcd1c5a277847e880811263f5c96809.png
[20200511223123529.png]: /images/20230312/bda1b5c43c744c3ea239ae4b7ddff9cc.png
[20200511223330923.png]: /images/20230312/3886445dfce340878d30559f8863c4f9.png
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