multipartrequest.java

java实现的透明信息上传组件

package test;

import java.util.Map;
import java.util.HashMap;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.fileupload.util.Streams;
import javax.servlet.http.HttpServletRequestWrapper;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class MultipartRequest extends HttpServletRequestWrapper {

	HashMap parameters = new HashMap();
	HashMap files = new HashMap();

	public MultipartRequest(HttpServletRequest request)
			throws FileUploadException, IOException {

		super(request);
		DiskFileItemFactory dff = new DiskFileItemFactory();
		dff.setSizeThreshold(1024 * 1024); // 内存最多存储1MB数据,超过就用临时目录缓存
		ServletFileUpload sfu = new ServletFileUpload(dff);
		sfu.setSizeMax(1024 * 1024 * 10); // 最多上传10MB数据
		sfu.setHeaderEncoding("utf-8");

		FileItemIterator fii = sfu.getItemIterator(request);

		while (fii.hasNext()) {
			FileItemStream fis = fii.next();
			
			if (fis.isFormField()) {
				InputStream stream = fis.openStream();
				String fieldName = fis.getFieldName();
				String content = null;
				content = Streams.asString(stream, "utf-8");
				setParameter(fieldName, content);
			} else {
				String pathSrc = fis.getName();
				if (pathSrc.trim().equals("")) {

					continue;
				}
				String fieldName = fis.getFieldName();
				files.put(fieldName, fis);
			}
		}

	}

	private void setParameter(String fieldName, String content) {

		String[] mValue = (String[]) parameters.get(fieldName);
		if (mValue == null) {

			mValue = new String[0];
		}
		String[] newValue = new String[mValue.length + 1];
		System.arraycopy(mValue, 0, newValue, 0, mValue.length);
		newValue[mValue.length] = content;
		parameters.put(fieldName, newValue);
	}

	public String getParameter(String name) {
		String[] mValue = (String[]) parameters.get(name);
		if ((mValue != null) && (mValue.length > 0)) {

			return mValue[0];

		}

		return null;
	}

	public Enumeration getParameterNames() {

		Collection c = parameters.keySet();

		return Collections.enumeration(c);

	}

	public String[] getParameterValues(String name) {

		String[] mValue = (String[]) parameters.get(name);
		return mValue;

	}

	public Map getParameterMap() {

		return parameters;
	}

	public FileItemStream getFileItem(String name) {

		FileItemStream fItem = (FileItemStream) files.get(name);
		return fItem;
	}

	public Enumeration getFileItemNames() {

		Collection c = files.keySet();
		return Collections.enumeration(c);

	}

}