Java WS和二进制数据传送

(一) 有关介绍

二进制数据在WS中传送,可以有两种方式:

1 把数据直接作为xml文档中某元素的字节流,作为XML解析器要解析的一部分,很明显这种方式比较低效.

2 二进制数据作为附件,作为带外(out of band)数据随同XML发送, 提高了效率.目前这类处理有几个规范:

DIME(直接 Internet 消息封装),这个数据包装格式及其处理,只有微软在支持.

http://www.microsoft.com/china/msdn/archives/library/dnwebsrv/html/DIMEWSAttch.asp

http://www.zdnet.com.cn/developer/code/story/0,3800066897,39358789,00.htm

MTOM(SOAP 消息传输优化机制)和XOP(二进制 XML 优化封装);

在Sun规范JAX-RPC1.1中,要求使用SwA(SOAP with Attachments) 支持附件,为此Sun提供了SOAP with Attachments API for Java,带附件的SoapAPI(SAAJ),早期它和jaxm合在一起的,现在已经独立开来形成了soap包,这个API专门用来处理Soap附件的所有操作.

JAXRPC 1.1 规范定义了MIME类型到Java类型的影射.

MIME Type

Java Type

image/gif

java.awt.Image

image/jpeg

java.awt.Image

text/plain

java.lang.String

multipart/*

javax.mail.internet.MimeMultipart

text/xml or application/xml

javax.xml.transform.Source

JAXRPC 1.1 规范定义了这种情况:当绑定到上表中没有定义的类型影射或者是绑定到备用MIME类型时,它应该影射到 javax.activation.DataHandler.

wscompile工具中的选项-f:<features>用于类型影射的项:datahandleronly,该项指明总是把附件影射到DataHandler类型.

(二) 编写例子应用

文件清单

SEI接口类IImage.java,实现SEI接口的类IIMageImpl.java,描述文件信息的值类型类FileInfo.java,Web应用部署描述文件web.xml,WS发布配置文件jaxrpc-ri.xml,WS编译配置文件config-interface.xml,构建客户端桩的config-wsdl.xml,构建文件build.xml

客户端测试类:MainBrowser.java,ImageListProvider.java和ImageLabelProvider.java,测试使用了SWT和JFace,请适当配置你的Eclipse环境,引入适当的库.

这个例子是从SEI开始,绑定样式为 RPC.

IImage.java清单:

package com.bin;

import java.rmi.Remote;

import java.rmi.RemoteException;

import javax.activation.*;

import javax.xml.soap.*;

import java.util.*;

public interface IImage extends Remote {

public DataHandler fetchImg(String sn) throws RemoteException;

public ArrayList fetchImgs(String[] sn) throws RemoteException;

public SOAPMessage construcMsg(String[] fn) throws RemoteException;

public ArrayList fetchFileList() throws java.rmi.RemoteException;

public FileInfo getFileList(String fn) throws java.rmi.RemoteException;

}

实现类 ImageImpl.java清单:

package com.bin;

import javax.xml.soap.*;

import java.net.*;

import java.util.*;

import java.io.*;

import javax.activation.*;

import java.rmi.*;

import java.awt.*;

import javax.xml.rpc.ServiceException;

import javax.xml.rpc.server.*;

import javax.xml.rpc.handler.soap.SOAPMessageContext;

import javax.xml.rpc.handler.MessageContext;

import javax.servlet.ServletContext;

import com.sun.xml.rpc.server.*;

public class ImageImpl implements IImage, ServiceLifecycle {

ServletEndpointContext servletEndpointContext = null;

String binarypath = "";

ArrayList al;

ServletContext servletContext = null;

public void init(Object p0) throws ServiceException {

// Some logic to do upon service creation

servletEndpointContext = (ServletEndpointContext) p0;

servletContext = servletEndpointContext.getServletContext();

binarypath = servletContext.getInitParameter("BinaryPath");

}

public void destroy() {

// Some logic to do on service destruction - e.g. clean up JDBC

servletEndpointContext = null;

servletContext = null;

}

public ArrayList fetchFileList() throws RemoteException {

File file = new File(this.binarypath);

//System.out.println(this.binarypath);

if (al == null)

al = new ArrayList();

File[] c = file.listFiles();

for (int i = 0; i < c.length; i++) {

FileInfo fi = new FileInfo();

fi.setIsdir(c[i].isDirectory());

fi.setFilename(c[i].getName());

fi.setFilelength(c[i].length());

fi.setFilepath(c[i].getAbsolutePath());

fi.setCreatedate(new Date(c[i].lastModified()));

al.add(fi);

}

return al;

}

public DataHandler fetchImg(String sn) throws RemoteException {

File file = new File(sn);

DataHandler dataHandler = null;

try {

URL url = new URL(file.toURL().toString());

dataHandler = new DataHandler(url);

} catch (Exception ex) {

System.out.println(ex);

throw new RemoteException(ex.getMessage());

}

return dataHandler;

}

public ArrayList fetchImgs(String[] fn) throws RemoteException {

ArrayList al = new ArrayList();

try {

for (int i = 0; i < fn.length; i++) {

File file = new File(fn[i]);

// Create attachment part for image

URL url = new URL(file.toURL().toString());

DataHandler dataHandler = new DataHandler(url);

al.add(dataHandler);

}

} catch (Exception ex) {

System.out.println(ex);

throw new RemoteException(ex.getMessage());

}

return al;

}

public SOAPMessage construcMsg(String[] fn) throws RemoteException {

FileReader fr = null;

BufferedReader br = null;

String line = "";

SOAPMessage message = null;

try {

// Create message factory

MessageFactory messageFactory = MessageFactory.newInstance();

// Create a message

message = messageFactory.createMessage();

// Get the SOAP header and body from the message

// and remove the header

SOAPHeader header = message.getSOAPHeader();

SOAPBody body = message.getSOAPBody();

header.detachNode();

for (int i = 0; i < fn.length; i++) {

File file = new File(fn[i]);

// Create attachment part for image

URL url = new URL(file.toURL().toString());

DataHandler dataHandler = new DataHandler(url);

AttachmentPart attachment2 = message

.createAttachmentPart(dataHandler);

attachment2.setContentId(file.getName());

message.addAttachmentPart(attachment2);

}

} catch (IOException e) {

System.out.println("I/O exception: " + e.toString());

throw new RemoteException(e.getMessage());

} catch (Exception ex) {

ex.printStackTrace();

throw new RemoteException(ex.getMessage());

}

return message;

}

public FileInfo getFileList(String fn) throws RemoteException {

// TODO Auto-generated method stub

File file = new File(fn);

FileInfo fi = new FileInfo();

fi.setFilename(file.getName());

fi.setFilelength(file.length());

fi.setFilepath(file.getAbsolutePath());

fi.setCreatedate(new Date(file.lastModified()));

return fi;

}

FileInfo.java清单:

package com.bin;

import java.util.Date;

/**

* 这是一个值类型,既然是值类型,它满足:

1 必须有缺省构造器. 2 必须没有实现Remote(直接的或是间接的). 3属性类型必须是JAX-RPC支持的类型.

public class FileInfo {

private String filename;

private String filepath;

private long filelength;

private Date createdate;

private boolean isdir = false;

public FileInfo() {

}

public Date getCreatedate() {

return createdate;

}

public void setCreatedate(Date createdate) {

this.createdate = createdate;

}

public long getFilelength() {

return filelength;

}

public void setFilelength(long filelength) {

this.filelength = filelength;

}

public String getFilename() {

return filename;

}

public void setFilename(String filename) {

this.filename = filename;

}

public String getFilepath() {

return filepath;

}

public void setFilepath(String filepath) {

this.filepath = filepath;

}

public String toString() {

return this.filename + this.getFilepath() + this.getFilelength();

}

public boolean isIsdir() {

return isdir;

}

public void setIsdir(boolean isdir) {

this.isdir = isdir;

}

web.xml清单:

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"

version="2.4">

<context-param>

<param-name>BinaryPath</param-name>

<param-value>更改成你的本地文件路径</param-value>

</context-param>

<welcome-file-list>

<welcome-file>index.htm</welcome-file>

<welcome-file>index.jsp</welcome-file>

<welcome-file>index.jws</welcome-file>

</welcome-file-list>

</web-app>

config-interface.xml清单:

<?xml version="1.0" encoding="UTF-8"?>

<service name="BinaryService" targetNamespace="urn:binary"

typeNamespace="urn:binary" packageName="com.binary">

<interface name="com.bin.IImage"

servantName="com.bin.ImageImpl" />

</service>

</configuration>

config-wsdl.xml清单:

<?xml version="1.0" encoding="UTF-8"?>

<wsdl location="http://localhost:8080/skysoft/binary?WSDL"

packageName="com.binary" />

</configuration>

jaxrpc-ri.xml清单:

<?xml version="1.0" encoding="UTF-8"?>

<webServices xmlns="http://java.sun.com/xml/ns/jax-rpc/ri/dd"

version="1.0"

targetNamespaceBase="http://java.sun.com/xml/ns/jax-rpc/wsi/wsdl"

typeNamespaceBase="http://java.sun.com/xml/ns/jax-rpc/wsi/types"

urlPatternBase="/ws">

<endpoint name="binaryservice" displayName="Stock Example"

description="Binary Web Service endpoint"

interface="com.bin.IImage" implementation="com.bin.ImageImpl"

model="/WEB-INF/model.xml.gz" />

</webServices>

构建文件build.xml:依次运行build,create-war,deploy,genstaticstub等任务,这样本例中的WS所需要的文件全部生成.

<?xml version="1.0" encoding="GBK"?>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

</property>

<!--fileset dir="${jaxrpc.lib.dir}">

</fileset-->

</fileset>

</fileset>

</fileset>

</fileset>

</path>

<!--fileset dir="${jaxrpc.lib.dir}">

</fileset-->

</fileset>

</fileset>

</fileset>

</path>

</taskdef>

</taskdef>

</target>

</wscompile>

</target>

</wscompile>

</target>

</wsdeploy>

</target>

</copy>

</copy>

</war>

</target>

</wscompile>

</target>

</project>

接下来,发布skysoft.war到你的web服务环境,本例使用的是Tomcat5,检查http://localhost:8080/skysoft/binary?WSDL是否装入.

发布成功后,用Eclipse新建一个java项目,把静态桩文件悉数拷贝到该项目的src下,然后编写以下类:

MainBrowser窗口类,显示图文件.

package swtui;

import java.io.IOException;

import java.rmi.RemoteException;

import java.util.ArrayList;

import javax.xml.rpc.Stub;

import org.eclipse.jface.resource.ImageDescriptor;

import org.eclipse.jface.viewers.ISelectionChangedListener;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.jface.viewers.SelectionChangedEvent;

import org.eclipse.jface.viewers.TableViewer;

import org.eclipse.jface.window.ApplicationWindow;

import org.eclipse.swt.SWT;

import org.eclipse.swt.custom.SashForm;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.graphics.ImageData;

import org.eclipse.swt.widgets.*;

import com.binary.BinaryService_Impl;

import com.binary.FileInfo;

import com.binary.IImage;

import com.binary.IImage_Stub;

public class MainBrowser extends ApplicationWindow {

Label label;

ImageLabelProvider canvas;

Image image;

public MainBrowser(Shell arg0) {

super(arg0);

// TODO Auto-generated constructor stub

}

public MainBrowser() {

super(null);

addStatusLine();

// TODO Auto-generated constructor stub

}

/**

* ImageLoader Currently supported image formats are:

* BMP (Windows Bitmap) ICO (Windows Icon) JPEG GIF PNG

protected Control createContents(Composite parent) {

getShell().setText("JFace File Explorer");

SashForm sash_form = new SashForm(parent, SWT.HORIZONTAL | SWT.NULL);

TableViewer tbv = new TableViewer(sash_form, SWT.BORDER

| SWT.FULL_SELECTION | SWT.MULTI);

ImageListProvider img = new ImageListProvider();

tbv.setContentProvider(img);

tbv.setInput(getFileInfo());

tbv.addSelectionChangedListener(new ISelectionChangedListener() {

public void selectionChanged(SelectionChangedEvent event) {

IStructuredSelection selection = (IStructuredSelection) event

.getSelection();

FileInfo fi = (FileInfo) selection.getFirstElement();

if (!fi.isIsdir()) {

showImage(fi.toString());

canvas.adjustSize();

// canvas.redraw();

}

setStatus(fi.toString());

}

});

canvas = new ImageLabelProvider(sash_form, SWT.SHELL_TRIM

| SWT.NO_BACKGROUND | SWT.NO_REDRAW_RESIZE | SWT.V_SCROLL

| SWT.H_SCROLL | SWT.CENTER);

return sash_form;

}

public static void main(String[] args) {

MainBrowser w = new MainBrowser();

w.setBlockOnOpen(true);

w.open();

}

public void showImage(String fn) {

IImage_Stub stub = (IImage_Stub) createProxy();

IImage hello = (IImage) stub;

ImageData idata = null;

try {

idata = new ImageData(hello.fetchImg(fn).getInputStream());

} catch (RemoteException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

ImageDescriptor id = ImageDescriptor.createFromImageData(idata);

if (image != null)

image.dispose();

image = id.createImage();

// label.setImage(id.createImage());

// canvas.setData(image);

canvas.setImage(image);

}

public Object getFileInfo() {

IImage_Stub stub = (IImage_Stub) createProxy();

IImage hello = (IImage) stub;

ArrayList al = null;

try {

al = hello.fetchFileList();

} catch (RemoteException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return al;

}

private Stub createProxy() {

return (Stub) (new BinaryService_Impl().getIImagePort());

}

ImageLabelProvider标签类,能滚动图象的组件.

package swtui;

import org.eclipse.swt.graphics.GC;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.widgets.Canvas;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Listener;

import org.eclipse.swt.widgets.ScrollBar;

import org.eclipse.swt.*;

public class ImageLabelProvider extends Canvas {

ScrollBar hBar = null;

ScrollBar vBar = null;

private Image image;

public Image getImage() {

return image;

}

public void setImage(Image image) {

this.image = image;

setData(image);

}

public ImageLabelProvider() {

this(null, SWT.CENTER);

// TODO Auto-generated constructor stub

}

public ImageLabelProvider(Composite arg0, int arg1) {

super(arg0, arg1);

hBar = getHorizontalBar();

vBar = getVerticalBar();

setListener();

// TODO Auto-generated constructor stub

}

public void adjustSize() {

if(image==null)

return;

final Point origin = new Point(0, 0);

Rectangle rect = image.getBounds();

Rectangle client = getClientArea();

hBar.setMaximum(rect.width);

vBar.setMaximum(rect.height);

hBar.setThumb(Math.min(rect.width, client.width));

vBar.setThumb(Math.min(rect.height, client.height));

int hPage = rect.width - client.width;

int vPage = rect.height - client.height;

int hSelection = hBar.getSelection();

int vSelection = vBar.getSelection();

if (hSelection >= hPage) {

if (hPage <= 0)

hSelection = 0;

origin.x = -hSelection;

}

if (vSelection >= vPage) {

if (vPage <= 0)

vSelection = 0;

origin.y = -vSelection;

}

redraw();

}

private void setListener() {

final Point origin = new Point(0, 0);

hBar.addListener(SWT.Selection, new Listener() {

public void handleEvent(Event e) {

int hSelection = hBar.getSelection();

int destX = -hSelection - origin.x;

Rectangle rect = image.getBounds();

scroll(destX, 0, 0, 0, rect.width, rect.height, false);

origin.x = -hSelection;

}

});

vBar.addListener(SWT.Selection, new Listener() {

public void handleEvent(Event e) {

int vSelection = vBar.getSelection();

int destY = -vSelection - origin.y;

Rectangle rect = getBounds();

scroll(0, destY, 0, 0, rect.width, rect.height, false);

origin.y = -vSelection;

}

});

addListener(SWT.Resize, new Listener() {

public void handleEvent(Event e) {

Rectangle rect = image.getBounds();

Rectangle client = getClientArea();

hBar.setMaximum(rect.width);

vBar.setMaximum(rect.height);

hBar.setThumb(Math.min(rect.width, client.width));

vBar.setThumb(Math.min(rect.height, client.height));

int hPage = rect.width - client.width;

int vPage = rect.height - client.height;

int hSelection = hBar.getSelection();

int vSelection = vBar.getSelection();

if (hSelection >= hPage) {

if (hPage <= 0)

hSelection = 0;

origin.x = -hSelection;

}

if (vSelection >= vPage) {

if (vPage <= 0)

vSelection = 0;

origin.y = -vSelection;

}

redraw();

}

});

addListener(SWT.Paint, new Listener() {

public void handleEvent(Event e) {

GC gc = e.gc;

gc.drawImage(image, origin.x, origin.y);

Rectangle rect = image.getBounds();

Rectangle client = getClientArea();

int marginWidth = client.width - rect.width;

if (marginWidth > 0) {

gc.fillRectangle(rect.width, 0, marginWidth, client.height);

}

int marginHeight = client.height - rect.height;

if (marginHeight > 0) {

gc.fillRectangle(0, rect.height, client.width,

marginHeight);

}

});

}

ImageListProvider.java代码清单:

package swtui;

import java.io.File;

import java.rmi.RemoteException;

import java.util.ArrayList;

import javax.xml.rpc.Stub;

import org.eclipse.jface.viewers.IStructuredContentProvider;

import org.eclipse.jface.viewers.Viewer;

import com.binary.*;

public class ImageListProvider implements IStructuredContentProvider{

public Object[] getElements1(Object element) {

Object[] kids = ((ArrayList) element).toArray();

return kids == null ? new Object[0] : kids;

}

private Stub createProxy() {

return (Stub) (new BinaryService_Impl().getIImagePort());

}

public void dispose() {

}

public void inputChanged(Viewer arg0, Object arg1, Object arg2) {

}

到此,例子结束,应该说使用Eclipse,借助于插件,开发一个web服务还是相当快捷的. 本例可通过扩展客户端以处理其它格式的文件.

下一篇将介绍如何在C#中调用这个服务.