JSF自定义文件上传组件

 相信有很多使用JSF的人都和我一样比较青睐于SUN 的官方实现，但同时我们会遇到一些不方便，文件上传就是其中之一。当然我们可以选择其它实现如开源 myfaces甚至收费的实现richfaces。不过我们同样可以开发自己的组件，在这里我就以一个基于JSF1.2的文 件上传组件为例介绍jsf组件开发（其中我参考了jsf1.2和myfaces1.1的源代码，开源真是好啊）。

1、准备：

        先新建工程，如JSFX，并引入commons- fileupload.jar和commons-io.jar两个包（版本为1.2），源文件目录结构如下：

        

      

         jsf官方实现默认是不支持multipart/form -data类型的表单的，为了使jsf能够解析multipart/form-data表单的数据，我参考了myfaces1.1的方式，然 后按照commons-fileupload1.2重构了部分代码（myfaces1.1使用的是commons-fileupload1.1）

        myfaces之所以能处理multipart/form-data类型的 表单，关键就在于MultipartFilter和MultipartRequestWrapper这两个类，下面是我的代码：

MultipartFilter.java：

1. package com.jsfx.filter;
3. import java.io.IOException;
5. import javax.servlet.Filter;
6. import javax.servlet.FilterChain;
7. import javax.servlet.FilterConfig;
8. import javax.servlet.ServletException;
9. import javax.servlet.ServletRequest;
10. import javax.servlet.ServletResponse;
11. import javax.servlet.http.HttpServletRequest;
12. import javax.servlet.http.HttpServletResponse;
14. import org.apache.commons.fileupload.servlet.ServletFileUpload;
15. /**
16.  * 用以解析multipart表单的过滤器
17.  * 代码主要来自myFaces1.1的MultipartFilter类
18.  * 主要区别是使用了commons-fileupload1.2处理文件上传
19.  * */
20. public class MultipartFilter implements Filter {
22.     private int uploadMaxFileSize = 10 * 1024 * 1024; // 默认文件最大大小为10 MB
24.     private int uploadThresholdSize = 1 * 1024 * 1024; // 默认临界值大小为1 MB（即超过1m的文件将使用缓存）
26.     private String uploadRepositoryPath = null;//临时文件夹，默认为空，由虚拟机分配
28.     public void init(FilterConfig filterConfig) {
29.         uploadMaxFileSize = resolveSize(filterConfig
30.                 .getInitParameter("uploadMaxFileSize"), uploadMaxFileSize);
31.         uploadThresholdSize = resolveSize(filterConfig
32.                 .getInitParameter("uploadThresholdSize"), uploadThresholdSize);
33.         uploadRepositoryPath = filterConfig
34.                 .getInitParameter("uploadRepositoryPath");
35.     }
36.     public void doFilter(ServletRequest request, ServletResponse response,
37.             FilterChain chain) throws IOException, ServletException {
38.         if (!(response instanceof HttpServletResponse)) {
39.             chain.doFilter(request, response);
40.             return;
41.         }
43.         HttpServletRequest httpRequest = (HttpServletRequest) request;
44.         if (ServletFileUpload.isMultipartContent(httpRequest)) {//判断表单类型
45.             chain.doFilter(new MultipartRequestWrapper(httpRequest,
46.                     uploadMaxFileSize, uploadThresholdSize,
47.                     uploadRepositoryPath), response);
48.             //如果为multipart类型，对request进行包装，使jsf能解析表单数据
49.         } else {
50.             chain.doFilter(request, response);
51.         }
52.     }
54.     public void destroy() {
55.     }
57.     private int resolveSize(String param, int defaultValue) {
58.         int numberParam = defaultValue;
60.         if (param != null) {
61.             param = param.toLowerCase();
62.             int factor = 1;
63.             String number = param;
65.             if (param.endsWith("g")) {
66.                 factor = 1024 * 1024 * 1024;
67.                 number = param.substring(0, param.length() - 1);
68.             } else if (param.endsWith("m")) {
69.                 factor = 1024 * 1024;
70.                 number = param.substring(0, param.length() - 1);
71.             } else if (param.endsWith("k")) {
72.                 factor = 1024;
73.                 number = param.substring(0, param.length() - 1);
74.             }
76.             numberParam = Integer.parseInt(number) * factor;
77.         }
78.         return numberParam;
79.     }
81. }

MultipartRequestWrapper.java

1. package com.jsfx.filter;
3. import java.io.File;
4. import java.io.UnsupportedEncodingException;
5. import java.util.Collections;
6. import java.util.Enumeration;
7. import java.util.HashMap;
8. import java.util.Iterator;
9. import java.util.List;
10. import java.util.Map;
12. import javax.faces.application.FacesMessage;
13. import javax.faces.context.FacesContext;
14. import javax.servlet.http.HttpServletRequest;
15. import javax.servlet.http.HttpServletRequestWrapper;
17. import org.apache.commons.fileupload.FileItem;
18. import org.apache.commons.fileupload.FileUploadBase;
19. import org.apache.commons.fileupload.FileUploadException;
20. import org.apache.commons.fileupload.disk.DiskFileItemFactory;
21. import org.apache.commons.fileupload.servlet.ServletFileUpload;
23. /**
24.  * Request的包装类，使jsf能解析表单数据 代码主要来自myFaces1.1的MultipartRequestWrapper类
25.  * 主要区别是使用了commons-fileupload1.2处理文件上传
26.  */
27. @SuppressWarnings("unchecked")
28. public class MultipartRequestWrapper extends HttpServletRequestWrapper {
29.     public static final String UPLOADED_FILES_ATTRIBUTE = "org.apache.myfaces.uploadedFiles";
30.     public static final String WWW_FORM_URLENCODED_TYPE = "application/x-www-form-urlencoded";
32.     HttpServletRequest request = null;
33.     HashMap parametersMap = null;// 参数表
34.     ServletFileUpload fileUpload = null;
35.     HashMap fileItems = null;// 上传文件表
36.     int maxSize;// 表单最大大小
37.     int thresholdSize;// 临界值大小
38.     String repositoryPath;// 临时文件夹位置
40.     public MultipartRequestWrapper(HttpServletRequest request, int maxSize,
41.             int thresholdSize, String repositoryPath) {
42.         super(request);
43.         this.request = request;
44.         this.maxSize = maxSize;
45.         this.thresholdSize = thresholdSize;
46.         this.repositoryPath = repositoryPath;
47.     }
48.     @Override
49.     public Enumeration getParameterNames() {
50.         if (parametersMap == null)
51.             parseRequest();
53.         return Collections.enumeration(parametersMap.keySet());
54.     }
55.     @Override
56.     public String getParameter(String name) {
57.         if (parametersMap == null)
58.             parseRequest();
60.         String[] values = (String[]) parametersMap.get(name);
61.         if (values == null)
62.             return null;
63.         return values[0];
64.     }
65.     @Override
66.     public String[] getParameterValues(String name) {
67.         if (parametersMap == null)
68.             parseRequest();
70.         return (String[]) parametersMap.get(name);
71.     }
72.     @Override
73.     public Map getParameterMap() {
74.         if (parametersMap == null)
75.             parseRequest();
77.         return parametersMap;
78.     }
80.     /**
81.      * 获取请求中的FileItem
82.      */
83.     public FileItem getFileItem(String fieldName) {
84.         if (fileItems == null)
85.             parseRequest();
86.         return (FileItem) fileItems.get(fieldName);
87.     }
89.     /**
90.      * 获取请求中的FileItem表
91.      */
92.     public Map getFileItems() {
93.         if (fileItems == null)
94.             parseRequest();
95.         return fileItems;
96.     }
97.     @Override
98.     public Object getAttribute(String string) {
99.         if (string.equals(UPLOADED_FILES_ATTRIBUTE)) {
100.             return getFileItems();
101.         }
102.         return super.getAttribute(string);
103.     }
104.     @Override
105.     public String getContentType() {
106.         return WWW_FORM_URLENCODED_TYPE;
107.     }
109.     /**
110.      * 最关键的部分，解析表单数据
111.      */
112.     private void parseRequest() {
113.         DiskFileItemFactory factory = new DiskFileItemFactory();
114.         factory.setSizeThreshold(thresholdSize);// 设置临届大小
115.         if (repositoryPath != null && repositoryPath.trim().length() > 0)
116.             factory.setRepository(new File(repositoryPath));// 设置临时文件夹
117.         fileUpload = new ServletFileUpload();
118.         fileUpload.setFileItemFactory(factory);
119.         fileUpload.setSizeMax(maxSize);// 设置表单最大大小
121.         String charset = request.getCharacterEncoding();
122.         fileUpload.setHeaderEncoding(charset);
124.         List requestParameters = null;
125.         try {
126.             requestParameters = fileUpload.parseRequest(request);
127.         } catch (FileUploadBase.SizeLimitExceededException e) {
128.             e.printStackTrace();
129.             FacesContext.getCurrentInstance().addMessage("",
130.                     new FacesMessage(e.getMessage()));// 文件超过大小时提示用户
131.             requestParameters = Collections.EMPTY_LIST;
133.         } catch (FileUploadException fue) {
134.             fue.printStackTrace();
135.             FacesContext.getCurrentInstance().addMessage("",
136.                     new FacesMessage(fue.getMessage()));
137.             requestParameters = Collections.EMPTY_LIST;
138.         }
140.         parametersMap = new HashMap(requestParameters.size());// 建立参数表
141.         fileItems = new HashMap();
143.         for (Iterator iter = requestParameters.iterator(); iter.hasNext();) {
144.             FileItem fileItem = (FileItem) iter.next();
145.             if (fileItem.isFormField()) {// 普通参数处理
146.                 String name = fileItem.getFieldName();
147.                 String value = null;
148.                 if (charset == null) {
149.                     value = fileItem.getString();
150.                 } else {
151.                     try {
152.                         value = new String(fileItem.get(), charset);
153.                     } catch (UnsupportedEncodingException e) {
154.                         value = fileItem.getString();
155.                     }
156.                 }
157.                 addTextParameter(name, value);// 添加参数
158.             } else {// 参数是一个文件
159.                 if (fileItem.getName() != null) {
160.                     fileItems.put(fileItem.getFieldName(), fileItem);// 添加Fileitem
161.                 }
162.             }
163.         }
165.         for (Iterator it = request.getParameterMap().entrySet().iterator(); it
166.                 .hasNext();) {
167.             Map.Entry entry = (Map.Entry) it.next();
169.             Object value = entry.getValue();
171.             if (value instanceof String[]) {
172.                 String[] valuesArray = (String[]) entry.getValue();
173.                 for (int i = 0; i < valuesArray.length; i++) {
174.                     addTextParameter((String) entry.getKey(), valuesArray[i]);
175.                 }
176.             } else if (value instanceof String) {
177.                 String strValue = (String) entry.getValue();
178.                 addTextParameter((String) entry.getKey(), strValue);
179.             } else if (value != null)
180.                 throw new IllegalStateException("value of type : "
181.                         + value.getClass() + " for key : " + entry.getKey()
182.                         + " cannot be handled.");
184.         }
185.     }
187.     private void addTextParameter(String name, String value) {
188.         if (!parametersMap.containsKey(name)) {
189.             String[] valuesArray = { value };
190.             parametersMap.put(name, valuesArray);
191.         } else {
192.             String[] storedValues = (String[]) parametersMap.get(name);
193.             int lengthSrc = storedValues.length;
194.             String[] valuesArray = new String[lengthSrc + 1];
195.             System.arraycopy(storedValues, 0, valuesArray, 0, lengthSrc);
196.             valuesArray[lengthSrc] = value;
197.             parametersMap.put(name, valuesArray);
198.         }
199.     }
200. }

最后在web.xml配置过滤器，sun的jsf实现就可以处理 multipart/form-data表单了。

web.xml：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4.     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
5.     <context-param>
6.         <param-name>javax.faces.CONFIG_FILES</param-name>
7.         <param-value>/WEB-INF/faces-config.xml</param-value>
8.     </context-param>
9.     <servlet>
10.         <servlet-name>Faces Servlet</servlet-name>
11.         <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
12.         <load-on-startup>0</load-on-startup>
13.     </servlet>
14.     <servlet-mapping>
15.         <servlet-name>Faces Servlet</servlet-name>
16.         <url-pattern>*.faces</url-pattern>
17.     </servlet-mapping>
18.     <description>=====配置过滤器=====</description>
19.     <filter>
20.         <filter-name>MultipartFilter</filter-name>
21.         <filter-class>com.jsfx.filter.MultipartFilter</filter-class>
22.     </filter>
23.     <filter-mapping>
24.         <filter-name>MultipartFilter</filter-name>
25.         <servlet-name>Faces Servlet</servlet-name>
26.     </filter-mapping>
27.     <description>==================</description>
28.     <welcome-file-list>
29.         <welcome-file>index.jsp</welcome-file>
30.     </welcome-file-list>
31. </web-app>

 

2、UploadedFile.java：作为标签的value存储上传文件相关属性的类。

1. package com.jsfx.fileupload;
3. import java.io.ByteArrayInputStream;
4. import java.io.File;
5. import java.io.IOException;
6. import java.io.InputStream;
8. import org.apache.commons.fileupload.FileItem;
10. public class UploadedFile {
11.     private String name;
12.     private String contentType;
13.     private FileItem fileItem;
15.     public UploadedFile(FileItem fileItem) throws IOException {
16.         this.name = fileItem.getName();
17.         this.contentType = fileItem.getContentType();
18.         this.fileItem = fileItem;
19.     }
21.     public void save(String file) {// 保存文件
22.         try {
23.             fileItem.write(new File(file));
24.         } catch (Exception e) {
25.             e.printStackTrace();
26.         }
27.     }
29.     public byte[] getBytes() throws IOException {
30.         byte[] bytes = new byte[(int) getSize()];
31.         if (fileItem != null)
32.             fileItem.getInputStream().read(bytes);
33.         return bytes;
34.     }
36.     public InputStream getInputStream() throws IOException {
37.         return fileItem != null ? fileItem.getInputStream()
38.                 : new ByteArrayInputStream(new byte[0]);
39.     }
41.     public String getContentType() {
42.         return contentType;
43.     }
45.     public String getName() {
46.         return name;
47.     }
49.     public long getSize() {
50.         return fileItem != null ? fileItem.getSize() : 0;
51.     }
52. }

UploadedFileConverter.java用来转化UploadedFile的类型

1. package com.jsfx.fileupload;
3. import javax.faces.component.UIComponent;
4. import javax.faces.context.FacesContext;
5. import javax.faces.convert.Converter;
6. import javax.faces.convert.ConverterException;
8. public class UploadedFileConverter implements Converter {
9.     public Object getAsObject(FacesContext facescontext,
10.             UIComponent uicomponent, String s) throws ConverterException {
11.         return null;
12.     }
14.     public String getAsString(FacesContext facescontext,
15.             UIComponent uicomponent, Object obj) throws ConverterException {
16.         if (obj instanceof UploadedFile) {
17.             return ((UploadedFile) obj).getName();
18.         } else {
19.             return null;
20.         }
21.     }
22. }

3、实现标签描述库，这里使用的UploadTag类，下面将会提到

jsfx.tld（注意看它在上面项目中的位置）

1. <?xml version="1.0" encoding="UTF-8"?>
2. <taglib version="2.1" xmlns="http://java.sun.com/xml/ns/javaee"
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4.     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee web-jsptaglibrary_2_1.xsd">
5.     <tlib-version>1.0</tlib-version>
6.     <short-name>x</short-name>
7.     <uri>http://jsfx.com/</uri>
8.     <tag>
9.         <name>upload</name>
10.         <tag-class>com.jsfx.fileupload.UploadTag</tag-class>
11.         <body-content>JSP</body-content>
12.         <description>
13.             为了简化开发只定义了几个必要和常用的属性如id，value，required，style，onchange等等
14.         </description>
15.         <attribute>
16.             <name>id</name>
17.             <rtexprvalue>true</rtexprvalue>
18.         </attribute>
19.         <attribute>
20.             <name>value</name>
21.             <rtexprvalue>false</rtexprvalue>
22.             <deferred-value>
23.                 <type>com.jsfx.fileupload.UploadedFile</type>
24.             </deferred-value>
25.         </attribute>
26.         <attribute>
27.             <name>converter</name>
28.             <rtexprvalue>false</rtexprvalue>
29.             <deferred-value>
30.                 <type>com.jsfx.fileupload.UploadedFileConvert</type>
31.             </deferred-value>
32.         </attribute>
33.         <attribute>
34.             <name>required</name>
35.             <rtexprvalue>false</rtexprvalue>
36.             <deferred-value>
37.                 <type>boolean</type>
38.             </deferred-value>
39.         </attribute>
40.         <attribute>
41.             <name>disabled</name>
42.             <rtexprvalue>false</rtexprvalue>
43.             <deferred-value>
44.                 <type>boolean</type>
45.             </deferred-value>
46.         </attribute>
47.         <attribute>
48.             <name>readonly</name>
49.             <rtexprvalue>false</rtexprvalue>
50.             <deferred-value>
51.                 <type>boolean</type>
52.             </deferred-value>
53.         </attribute>
54.         <attribute>
55.             <name>style</name>
56.             <rtexprvalue>false</rtexprvalue>
57.             <deferred-value>
58.                 <type>java.lang.String</type>
59.             </deferred-value>
60.         </attribute>
61.         <attribute>
62.             <name>styleClass</name>
63.             <rtexprvalue>false</rtexprvalue>
64.             <deferred-value>
65.                 <type>java.lang.String</type>
66.             </deferred-value>
67.         </attribute>
68.         <attribute>
69.             <name>onchange</name>
70.             <required>false</required>
71.             <deferred-value>
72.                 <type>java.lang.String</type>
73.             </deferred-value>
74.         </attribute>
75.     </tag>
76. </taglib>

一个jsf自定义组件通常由

（1）标签属性处理类：主要作用是从页面标签接收值。继承至UIComponentELTag，这里与jsf1.1不同，由于使用了统一EL表 达式。

（2）Component类：主要作用为在Server端保存及恢复组件状态。

（3）Renderer类： 主要功能是 在响应阶段将Java组件的属性转换为HTML代码，在接受请求阶段将HTML Request中传来的资料转换为Java组件的属性。

 

4、标签属性处理类：

UploadTag.java

1. package com.jsfx.fileupload;
3. import javax.faces.component.UIComponent;
4. import javax.faces.context.FacesContext;
5. import javax.faces.convert.Converter;
6. import javax.faces.webapp.UIComponentELTag;
7. import javax.servlet.jsp.JspException;
9. public class UploadTag extends UIComponentELTag {
10.     private javax.el.ValueExpression value;
11.     private javax.el.ValueExpression converter;
12.     private javax.el.ValueExpression styleClass;
13.     private javax.el.ValueExpression disabled;
14.     private javax.el.ValueExpression required;
15.     private javax.el.ValueExpression style;
16.     private javax.el.ValueExpression onchange;
18.     @Override
19.     public String getComponentType() {
20.         return "HtmlUpload";//返回Component的类型，在faces-config.xml中找到相应的类
21.     }
23.     @Override
24.     public String getRendererType() {
25.         return "UploadRenderer";//返回Renderer的类型，在faces-config.xml中找到相应的类
26.     }
28.     public void setValue(javax.el.ValueExpression value) {
29.         this.value = value;
30.     }
32.     public void setConverter(javax.el.ValueExpression converter) {
33.         this.converter = converter;
34.     }
36.     public void setRequired(javax.el.ValueExpression required) {
37.         this.required = required;
38.     }
40.     public void setDisabled(javax.el.ValueExpression disabled) {
41.         this.disabled = disabled;
42.     }
44.     public void setStyle(javax.el.ValueExpression style) {
45.         this.style = style;
46.     }
48.     public void setStyleClass(javax.el.ValueExpression styleClass) {
49.         this.styleClass = styleClass;
50.     }
52.     public void setOnchange(javax.el.ValueExpression onchange) {
53.         this.onchange = onchange;
54.     }
56.     @Override
57.     protected void setProperties(UIComponent component) {
58.         super.setProperties(component);
59.         javax.faces.component.UIInput input = null;
60.         try {
61.             input = (javax.faces.component.UIInput) component;
62.         } catch (ClassCastException cce) {
63.             throw new IllegalStateException(
64.                     "Component "
65.                             + component.toString()
66.                             + " not expected type.  Expected: javax.faces.component.UIInput.  Perhaps you're missing a tag?");
67.         }
69.         if (converter != null) {
70.             if (!converter.isLiteralText()) {
71.                 input.setValueExpression("converter", converter);
72.             } else {
73.                 Converter conv = FacesContext.getCurrentInstance()
74.                         .getApplication().createConverter(
75.                                 converter.getExpressionString());
76.                 input.setConverter(conv);
77.             }
78.         }
80.         if (value != null) {
81.             input.setValueExpression("value", value);
82.         }
84.         if (required != null) {
85.             input.setValueExpression("required", required);
86.         }
88.         if (disabled != null) {
89.             input.setValueExpression("disabled", disabled);
90.         }
91.         if (style != null) {
92.             input.setValueExpression("style", style);
93.         }
94.         if (styleClass != null) {
95.             input.setValueExpression("styleClass", styleClass);
96.         }
97.         if (onchange != null) {
98.             input.setValueExpression("onchange", onchange);
99.         }
100.     }
102.     @Override
103.     public int doStartTag() throws JspException {
104.         try {
105.             return super.doStartTag();
106.         } catch (Exception e) {
107.             Throwable root = e;
108.             while (root.getCause() != null) {
109.                 root = root.getCause();
110.             }
111.             throw new JspException(root);
112.         }
113.     }
115.     @Override
116.     public int doEndTag() throws JspException {
117.         try {
118.             return super.doEndTag();
119.         } catch (Exception e) {
120.             Throwable root = e;
121.             while (root.getCause() != null) {
122.                 root = root.getCause();
123.             }
124.             throw new JspException(root);
125.         }
126.     }
128.     @Override
129.     public void release() {
130.         super.release();
131.         this.value = null;
132.         this.converter = null;
133.         this.disabled = null;
134.         this.style = null;
135.         this.styleClass = null;
136.         this.required = null;
137.         this.onchange = null;
138.     }
139. }

5、Component类

HtmlUpload.java

1. package com.jsfx.fileupload;
3. import java.util.ArrayList;
4. import java.util.List;
6. import javax.el.ValueExpression;
7. import javax.faces.component.UIInput;
9. public class HtmlUpload extends UIInput {
11.     private java.lang.Boolean disabled;
12.     private java.lang.String style;
13.     private java.lang.String styleClass;
14.     private java.lang.String onchange;
16.     public java.lang.String getOnchange() {
17.         if (null != this.onchange) {
18.             return this.onchange;
19.         }
20.         ValueExpression _ve = getValueExpression("onchange");
21.         if (_ve != null) {
22.             return (java.lang.String) _ve.getValue(getFacesContext()
23.                     .getELContext());
24.         } else {
25.             return null;
26.         }
27.     }
29.     public void setOnchange(java.lang.String onchange) {
30.         this.onchange = onchange;
31.         handleAttribute("onchange", onchange);
32.     }
34.     public boolean isDisabled() {
35.         if (null != this.disabled) {
36.             return this.disabled;
37.         }
38.         ValueExpression _ve = getValueExpression("disabled");
39.         if (_ve != null) {
40.             return (java.lang.Boolean) _ve.getValue(getFacesContext()
41.                     .getELContext());
42.         } else {
43.             return false;
44.         }
45.     }
47.     public void setDisabled(boolean disabled) {
48.         this.disabled = disabled;
49.     }
51.     public java.lang.String getStyle() {
52.         if (null != this.style) {
53.             return this.style;
54.         }
55.         ValueExpression _ve = getValueExpression("style");
56.         if (_ve != null) {
57.             return (java.lang.String) _ve.getValue(getFacesContext()
58.                     .getELContext());
59.         } else {
60.             return null;
61.         }
62.     }
64.     public void setStyle(java.lang.String style) {
65.         this.style = style;
66.         handleAttribute("style", style);
67.     }
69.     public java.lang.String getStyleClass() {
70.         if (null != this.styleClass) {
71.             return this.styleClass;
72.         }
73.         ValueExpression _ve = getValueExpression("styleClass");
74.         if (_ve != null) {
75.             return (java.lang.String) _ve.getValue(getFacesContext()
76.                     .getELContext());
77.         } else {
78.             return null;
79.         }
80.     }
82.     public void setStyleClass(java.lang.String styleClass) {
83.         this.styleClass = styleClass;
84.     }
86.     public HtmlUpload() {
87.         super();
88.         setRendererType("TestRenderer");
89.     }
91.     @SuppressWarnings("unchecked")
92.     private void handleAttribute(String name, Object value) {
93.         List<String> setAttributes = null;
94.         setAttributes = (List<String>) this.getAttributes().get(
95.                 "javax.faces.component.UIComponentBase.attributesThatAreSet");
96.         if (setAttributes == null) {
97.             setAttributes = new ArrayList<String>(6);
98.             this
99.                     .getAttributes()
100.                     .put(
101.                             "javax.faces.component.UIComponentBase.attributesThatAreSet",
102.                             setAttributes);
103.         }
104.         if (value == null) {
105.             setAttributes.remove(name);
106.         } else if (!setAttributes.contains(name)) {
107.             setAttributes.add(name);
108.         }
109.     }
111. }

6、Renderer类

UploadRenderer.java

1. package com.jsfx.fileupload;
3. import java.io.IOException;
4. import java.util.Map;
6. import javax.faces.component.UIComponent;
7. import javax.faces.context.ExternalContext;
8. import javax.faces.context.FacesContext;
9. import javax.faces.context.ResponseWriter;
10. import javax.faces.convert.ConverterException;
11. import javax.servlet.ServletRequest;
12. import javax.servlet.http.HttpServletRequestWrapper;
14. import org.apache.commons.fileupload.FileItem;
16. import com.jsfx.filter.MultipartRequestWrapper;
17. import com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer;
19. public class UploadRenderer extends HtmlBasicInputRenderer {
20.     
21.     @Override
22.     /**
23.      * 生成<input: type=file/>的html标签
24.      * */
25.     protected void getEndTextToRender(FacesContext context,
26.             UIComponent component, String currentValue) throws IOException {
27.         String style = (String) component.getAttributes().get("style");
28.         String styleClass = (String) component.getAttributes()
29.                 .get("styleClass");
30.         Boolean disabled = (Boolean) component.getAttributes().get("disabled");
31.         String onchange = (String) component.getAttributes().get("onchange");
32.         ResponseWriter writer = context.getResponseWriter();
33.         assert (writer != null);
34.         writer.startElement("input", component);
35.         writeIdAttributeIfNecessary(context, writer, component);
36.         writer.writeAttribute("type", "file", null);
37.         writer.writeAttribute("name", (component.getClientId(context)),
38.                 "clientId");
39.         if (currentValue != null) {
40.             writer.writeAttribute("value", currentValue, "value");
41.         }
42.         if (null != styleClass) {
43.             writer.writeAttribute("class", styleClass, "styleClass");
44.         }
45.         if (null != style) {
46.             writer.writeAttribute("style", style, "style");
47.         }
48.         if (null != disabled) {
49.             writer.writeAttribute("disabled", disabled, "disabled");
50.         }
51.         if (null != onchange) {
52.             writer.writeAttribute("onchange", onchange, "onchange");
53.         }
54.         writer.endElement("input");
55.     }
57.     @Override
58.     @SuppressWarnings("unchecked")
59.     /**
60.      * 这个方法将取出Request中的文件数据，并将提交的“value” uploadedFile实例化
61.      * */
62.     public void decode(FacesContext facesContext, UIComponent uiComponent) {
63.         super.decode(facesContext, uiComponent);
64.         Object request = facesContext.getExternalContext().getRequest();
65.         if (!(request instanceof ServletRequest)) {
66.             ExternalContext externalContext = facesContext.getExternalContext();
67.             Map fileItems = (Map) externalContext.getRequestMap().get(
68.                     MultipartRequestWrapper.UPLOADED_FILES_ATTRIBUTE);
69.             FileItem fileItem = null;
70.             if (fileItems != null) {
71.                 String paramName = uiComponent.getClientId(facesContext);
72.                 fileItem = (FileItem) fileItems.get(paramName);
73.             }
74.             if (fileItem != null) {
75.                 try {
76.                     UploadedFile upFile;
77.                     upFile = new UploadedFile(fileItem);//实例化提交的value
78.                     ((HtmlUpload) uiComponent).setSubmittedValue(upFile);
79.                     ((HtmlUpload) uiComponent).setValid(true);
80.                 } catch (IOException ioe) {
81.                     ioe.printStackTrace();
82.                 }
83.             }
84.             return;
85.         }
86.         if (facesContext.getExternalContext().getRequest() instanceof ServletRequest) {
87.             ServletRequest multipartRequest = (ServletRequest) facesContext
88.                     .getExternalContext().getRequest();
89.             while (multipartRequest != null
90.                     && !(multipartRequest instanceof MultipartRequestWrapper)) {
91.                 if (multipartRequest instanceof HttpServletRequestWrapper) {
92.                     multipartRequest = ((HttpServletRequestWrapper) multipartRequest)
93.                             .getRequest();
94.                 } else {
95.                     multipartRequest = null;
96.                 }
97.             }
98.             if (multipartRequest != null) {
99.                 MultipartRequestWrapper mpReq = (MultipartRequestWrapper) multipartRequest;
101.                 String paramName = uiComponent.getClientId(facesContext);
102.                 FileItem fileItem = mpReq.getFileItem(paramName);
103.                 if (fileItem != null) {
104.                     try {
105.                         UploadedFile upFile;
106.                         upFile = new UploadedFile(fileItem);//实例化提交的value
107.                         ((HtmlUpload) uiComponent).setSubmittedValue(upFile);
108.                         ((HtmlUpload) uiComponent).setValid(true);
109.                     } catch (IOException ioe) {
110.                         ioe.printStackTrace();
111.                     }
112.                 }
113.             }
114.         }
115.     }
117.     @Override
118.     public Object getConvertedValue(FacesContext context,
119.             UIComponent component, Object submittedValue)
120.             throws ConverterException {
121.         if (submittedValue instanceof UploadedFile) {
122.             UploadedFile file = (UploadedFile) submittedValue;
123.             if (file.getName() != null && file.getName().length() > 0) {
124.                 return file;
125.             }
126.         }
127.         return null;
128.     }
129. }

7、整合

上面几个部分需要配置才能互相配合工作，这就需要UploadTag.java中的 getComponentType()、getRendererType()两个方法及配置文件。为了保证组件的独立性，我把faces-config.xml打包进了类的META-INF文件夹（见最上面项目的结构）。

faces-config.xml：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee"
3.     xmlns:xi="http://www.w3.org/2001/XInclude"
4.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
5.     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd">
6.     <component>
7.         <component-type>HtmlUpload</component-type>
8.         <component-class>
9.             com.jsfx.fileupload.HtmlUpload
10.         </component-class>
11.     </component>
12.     <render-kit>
13.         <renderer>
14.             <component-family>javax.faces.Input</component-family>
15.             <renderer-type>UploadRenderer</renderer-type>
16.             <renderer-class>
17.                 com.jsfx.fileupload.UploadRenderer
18.             </renderer-class>
19.         </renderer>
20.     </render-kit>
21. </faces-config>

8、打包

只要按照上面的目录结构打包就可以保证组件的独立性了，只需要配置web.xml的过滤 器

然后在需要的页面引入标签：<%@ taglib uri="http://jsfx.com/" prefix="x"%>

就可以像这样<x:upload id="upload" value="#{user.picture}" onchange="fileTypeCheck()"></x:upload>就可以使用标签了

注意：最好用jdk5编译，用高版本的话可能会与jsf1.2有冲突。

 

本来有个使用样例的，在这里就不贴出来了，到这里可以下载，包括上面所有源代码。

http://download.csdn.net/source/637158