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[J2ME]断点续传


断点续传的头信息设置：
conn.setRequestProperty("RANGE", "bytes=" + size + "-"); //断点续传

项目中使用断点续传，头信息的属性按上面设置好了，但无论怎么测试，就是不能实现，费了一天又一个晚上的功夫才查到问题所在，在使用断点续传的时候，头信息的联网方式设为了post，导致无法续传！

实践证明要实现断点续传：联网方式必须使用get方式，或默认不设置。

以下是断点续传的部分代码：
package com.xuudoo.booking;

import java.io.DataInputStream;
import java.io.IOException;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.rms.InvalidRecordIDException;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStoreException;
import javax.microedition.rms.RecordStoreNotOpenException;

import com.xuudoo.ewl.EWLScreen;

public class DownloadTool implements Runnable {
    public XItem item;//当前下载的item
    public String imageName;//当前下载的书名
    public int FocusID;//当前下载的ID

    public HttpConnection conn = null;
    public DataInputStream dis = null;
    public RMSRecorderIfno rms;//存放下载的漫画数据
    public RMSRecorderIfno rms1;//存放下载的url和数据节点个数
    public RMSRecorderIfno rms2; //存放废字节长度

    public DownloadTool(XItem xitem,int focusID) {
        item = xitem;
        imageName = xitem.itemId;
        FocusID = focusID;
    }

    public void run() {
        UIManager.isLoading = true;
        try {
            System.gc();
            String url = "";
            if (item.isResume){
                downloadFileagain(url);
            }else{
                url = UIManager._currMgz.mgzLocate;
                downloadFile(url);
            }
            UIManager._instance.doLoop();
            do {
                if (UIManager._instance.downloadurl == null)
                    break;
                for (int i = 0; i < UIManager._instance.downloadurl.size();) {
                    url = (String) UIManager._instance.downloadurl.elementAt(i);
                    item = (XItem) UIManager._instance.downloaditem.elementAt(i);
                    imageName = item.itemId;
                    FocusID = Integer.parseInt((String) UIManager._instance.downloadid.elementAt(i));
                    if (item.isResume)
                        downloadFileagain(url);
                    else
                        downloadFile(url);
                    break;
                }
                UIManager._instance.downloadurl.removeElement(url);
                UIManager._instance.downloaditem.removeElement(item);
                UIManager._instance.downloadid.removeElement(Integer.toString(FocusID));
                UIManager._instance.doLoop();
            } while (UIManager._instance.downloadurl != null && UIManager._instance.downloadurl.size() >= 1);
        } catch (Exception e) {
            if(BookingMidlet.DEBUG)
                e.printStackTrace();
        } finally {
            UIManager.isLoading = false;
            UIManager._instance.doLoop();
        }
    }

    public synchronized void StopDownLoadThread() {
        if (conn != null) {
            notify();
            Close();
        }
    }

    public synchronized void CloseMidlet() {
        if (dis != null) {
            try {
                dis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            dis = null;
        }
        if (conn != null) {
            notify();
            try {
                conn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            conn = null;
        }
        if (rms != null) {
            rms.close();
            rms  = null;
        }
        if (rms1 != null) {
            rms1.close();
            rms1  = null;
        }
        if (rms2 != null) {
            rms2.close();
            rms2  = null;
        }
        if(UIManager._instance._percent != null)
            UIManager._instance._percent = null;
    }
    
    private void Close() {
        if (dis != null) {
            try {
                dis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            dis = null;
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            conn = null;
        }
        try {
            Thread.sleep(500);
            if(BookingMidlet.DEBUG)
                System.out.println("-----关闭连接和RMS.");
        } catch (Exception ex) {
            //
        }
        if (rms != null) {
            rms.close();
            rms  = null;
        }
        if (rms1 != null) {
            rms1.close();
            rms1  = null;
        }
        if (rms2 != null) {
            rms2.close();
            rms2  = null;
        }
        if(UIManager._instance._percent != null)
            UIManager._instance._percent = null;
    }

    private int xcblength = 0; //整个xcb记录个数

    public void downloadFile(String url){
        if (RMSRecorderIfno.exists("002_" + imageName + "_mgz"))
            RMSRecorderIfno.delete("002_" + imageName + "_mgz");
        rms = new RMSRecorderIfno();
        rms.open("002_" + imageName + "_mgz", true);
        //
        rms2 = new RMSRecorderIfno();
        if (RMSRecorderIfno.exists("002_" + imageName + "_byte")) {
            RMSRecorderIfno.delete("002_" + imageName + "_byte");
        }
        rms2.open("002_" + imageName + "_byte", true);

        rms1 = new RMSRecorderIfno();
        rms1.open("002_" + imageName + "_url", true);
        byte[] urlbyte = url.getBytes();
        rms1.openWriteStream();
        rms1.write(urlbyte);
        rms1.addRecord(rms1.saveStreamToByteArray());
        rms1.closeWriteStream();
        String precentstr = "0";// 下载进度的百分比
        
        try {
            //S40_V3版本需通过cmwap才能下载
            if (!BookingMidlet.useProxy){
                conn = (HttpConnection)Connector.open(url);
            } else {
                String remainUrl = url.substring("http://".length());
                int index = remainUrl.indexOf("/");
                String path = "";
                if (index != -1) {
                    path = remainUrl.substring(index);
                    remainUrl = remainUrl.substring(0, index);
                }
                String host = "";
                String port = "";
                index = remainUrl.indexOf(":");
                if (index != -1) {
                    host = remainUrl.substring(0, index);
                    port = remainUrl.substring(index + 1);
                } else {
                    host = remainUrl;
                    port = null;
                }
                String proxyHost = "10.0.0.172";
                String proxyPort = "80";
                String cnwapUrl = "http://" + proxyHost + ":" + proxyPort + path;
                conn = (HttpConnection) Connector.open(cnwapUrl);
                if (port == null)
                    conn.setRequestProperty("X-Online-Host", host);
                else
                    conn.setRequestProperty("X-Online-Host", host + ":" + port);
            }
            dis = conn.openDataInputStream();
            // begin analyze db file
            dis.skip(0x50L);//RMS头 80个字节
            int recNum = dis.readInt();//xcb文件的节点数，4个字节
            rms1.openWriteStream();
            rms1.write(recNum);
            rms1.addRecord(rms1.saveStreamToByteArray());
            rms1.closeWriteStream();
            dis.skip(0x1CL);//28个字节的废字节
            for (int i = 0; i < recNum; i++) {
                if (BookingMidlet.limitDownloadSpeed){
                    try {
                        Thread.sleep(1000);
                    } catch (Exception ex) {
                        //
                    }
                }
                EWLScreen.instance.repaint();
                //16个字节是节点头
                dis.readInt();//4个字节的当前节点的序号
                dis.readInt();//4个字节的废字节
                int occupied = dis.readInt();//4个字节表示当前节点所在内存大小
                int recsize = dis.readInt();//4个字节表示当前节点的实际大小
                byte recdata[] = new byte[recsize];
                dis.readFully(recdata);
                
                if(BookingMidlet.DEBUG)
                    System.out.println("-----save rms data: "+recsize);
                // 以下代码用以计算下载百分比
                precentstr = "" + (100 * DownPrecent(rms)) / (recNum + 0.01);
                precentstr = forMatString(precentstr);
                UIManager._instance.set_percent(precentstr, FocusID);
                EWLScreen.prompt2 = precentstr;
                ////////////////////////////////////////////////////////////////////////
                rms.openWriteStream();
                rms.write(recdata);
                rms.addRecord(rms.saveStreamToByteArray());
                rms.closeWriteStream();
                
                //保存节点后面的废字节，以便续传时使用
                int Wastebytes = occupied - recsize - 16;
                rms2.openWriteStream();
                rms2.write(Wastebytes);
                rms2.addRecord(rms2.saveStreamToByteArray());
                rms2.closeWriteStream();
                dis.skip(Wastebytes); // subtract rec header
            }

            UIManager._instance.removeDownloadingItem(item);
            UIManager._instance.openDownloaded();
            UIManager._instance.insertDownloaded(item);
        } catch (Exception e) {
            if(BookingMidlet.DEBUG){
                System.out.println("-----中断下载。");
            }
//            UIManager.showAlert("下载失败！请删除后重新下载");
        } finally {
            Close();
        }
    }
    
    public void downloadFileagain(String url){
        try {
            if (RMSRecorderIfno.exists("002_" + imageName + "_mgz") && !item.isResume)
                RMSRecorderIfno.delete("002_" + imageName + "_mgz");
            rms = new RMSRecorderIfno();
            rms.open("002_" + imageName + "_mgz", true);
            //
            rms2 = new RMSRecorderIfno();
            if (RMSRecorderIfno.exists("002_" + imageName + "_byte") && !item.isResume) {
                RMSRecorderIfno.delete("002_" + imageName + "_byte");
            }
            rms2.open("002_" + imageName + "_byte", true);
            
            //以下代码用以断点续传
            rms1 = new RMSRecorderIfno();
            rms1.open("002_" + imageName + "_url", false);
            url = setValue(rms1);
            ////////////////////////////////////////////////////////////////////////////
            String precentstr = "0";// 下载进度的百分比
            precentstr = "" + (100 * DownPrecent(rms)) / (xcblength);
            precentstr = forMatString(precentstr);
            UIManager._instance.set_percent(precentstr, FocusID);
            //S40_V3版本需通过cmwap才能下载
            if (!BookingMidlet.useProxy){
                conn = (HttpConnection)Connector.open(url);
            } else {
                String remainUrl = url.substring("http://".length());
                int index = remainUrl.indexOf("/");
                String path = "";
                if (index != -1) {
                    path = remainUrl.substring(index);
                    remainUrl = remainUrl.substring(0, index);
                }
                String host = "";
                String port = "";
                index = remainUrl.indexOf(":");
                if (index != -1) {
                    host = remainUrl.substring(0, index);
                    port = remainUrl.substring(index + 1);
                } else {
                    host = remainUrl;
                    port = null;
                }
                String proxyHost = "10.0.0.172";
                String proxyPort = "80";
                String cnwapUrl = "http://" + proxyHost + ":" + proxyPort + path;
                conn = (HttpConnection) Connector.open(cnwapUrl);
                if (port == null)
                    conn.setRequestProperty("X-Online-Host", host);
                else
                    conn.setRequestProperty("X-Online-Host", host + ":" + port);
            }
            //设置Range
            int skipNum = RmsSize(rms, rms2);
            
            if (skipNum == 112) {
                dis = conn.openDataInputStream();
                dis.skip(0x50L);//RMS头 80个字节
                xcblength = dis.readInt();//xcb文件的节点数，4个字节
                rms1.openWriteStream();
                rms1.write(xcblength);
                rms1.setRecord(2, rms1.saveStreamToByteArray());
                rms1.closeWriteStream();
                dis.skip(0x1CL);//28个字节的废字节
            }else{
                conn.setRequestProperty("RANGE", "bytes=" + skipNum + "-");//断点续传
                dis = conn.openDataInputStream();
            }
            item.isResume = false;
            int num = DownPrecent(rms);
            for (int i = 0; i < xcblength - num; i++) {
                if (BookingMidlet.limitDownloadSpeed){
                    try {
                        Thread.sleep(1000);
                    } catch (Exception ex) {
                        //
                    }
                }
                EWLScreen.instance.repaint();
                //16个字节是节点头
                dis.readInt();//4个字节的当前节点的序号
                dis.readInt();//4个字节的废字节
                int occupied = dis.readInt();//4个字节表示当前节点所在内存大小
                int recsize = dis.readInt();//4个字节表示当前节点的实际大
                byte recdata[] = new byte[recsize];
                dis.readFully(recdata);

                rms.openWriteStream();
                rms.write(recdata);
                rms.addRecord(rms.saveStreamToByteArray());
                rms.closeWriteStream();

                precentstr = "" + (100 * DownPrecent(rms)) / (xcblength);
                precentstr = forMatString(precentstr);
                UIManager._instance.set_percent(precentstr, FocusID);

                //保存节点后面的废字节，以便续传时使用
                int Wastebytes = occupied - recsize - 16;
                rms2.openWriteStream();
                rms2.write(Wastebytes);
                rms2.addRecord(rms2.saveStreamToByteArray());
                rms2.closeWriteStream();
                dis.skip(Wastebytes); // subtract rec header
            }

            UIManager._instance.removeDownloadingItem(item);
            UIManager._instance.openDownloaded();
            UIManager._instance.insertDownloaded(item);
        } catch (Exception e) {
            if(BookingMidlet.DEBUG){
                System.out.println("-----中断下载。");
            }
            //UIManager.showAlert("下载失败！请删除后重新下载");
        } finally {
            Close();
        }

    }

    /**
     * 计算百分比
     * @param str
     * @return
     */
    public static String forMatString(String str) {
        String values;
        int index = str.indexOf(".");
        if(index != -1){
            values = str.substring(0, index);
        }else{
            values = str;
        }
        return values;
    }

    /**
     *  遍历RMS，得到当前记录个数
     * @param rms
     * @return
     */
    public int DownPrecent(RMSRecorderIfno rms) {
        int i = 0;
        try {
            RecordEnumeration enu = null;
            if (enu == null) {
                enu = rms.rs.enumerateRecords(null, null, false);
            }
            while (enu.hasNextElement()) {
                try {
                    enu.nextRecordId();
                } catch (InvalidRecordIDException e) {
                    e.printStackTrace();
                }
                i++;
            }
        } catch (RecordStoreNotOpenException e) {
            e.printStackTrace();
        }
        return i;
    }

    /**
     *  遍历RMS，计算当前记录的长度
     * @param rms
     * @param rms1
     * @return
     */
    public int RmsSize(RMSRecorderIfno _rms, RMSRecorderIfno _rms2) {
        int i = 112;
        try {
            RecordEnumeration enu = null;
            if (enu == null) {
                enu = _rms.rs.enumerateRecords(null, null, false);
            }
            while (enu.hasNextElement()) {
                try {
                    i += enu.nextRecord().length;
                    i += 16;
                } catch (InvalidRecordIDException e) {
                    e.printStackTrace();
                } catch (RecordStoreException e) {
                    e.printStackTrace();
                }
            }
        } catch (RecordStoreNotOpenException e) {
            e.printStackTrace();
        }
        i = i + sikpSize(_rms2);
        return i;
    }

    /**
     *  遍历RMS，计算rms中各个节点后跳过的节点大小
     * @param rms
     * @return
     */
    public int sikpSize(RMSRecorderIfno _rms2) {
        int len = 0;
        try {
            RecordEnumeration enu = null;
            if (enu == null) {
                enu = _rms2.rs.enumerateRecords(null, null, false);
            }
            while (enu.hasNextElement()) {
                try {
                    len += bytesToInt(enu.nextRecord());
                } catch (InvalidRecordIDException e) {
                    e.printStackTrace();
                } catch (RecordStoreException e) {
                    e.printStackTrace();
                }
            }
        } catch (RecordStoreNotOpenException e) {
            e.printStackTrace();
        }
        
        return len;
    }

    /**
     * byte转int
     * @param bytes
     * @return
     */
    public static int bytesToInt(byte[] bytes) {
        int result = 0;
        for (int i = 0; i < bytes.length; i++) {
            result <<= 8;
            result |= (bytes[i] & 0xff); //此处忽略byte的符号位   
        }
        return result;
    }
    
    private String setValue(RMSRecorderIfno rms){
        String url = "";
        RecordEnumeration enu = null;
        if (enu == null) {
            try {
                enu = rms.rs.enumerateRecords(null, null, false);
            } catch (RecordStoreNotOpenException e) {
                e.printStackTrace();
            }
            int i = 0;
            while (enu.hasNextElement()) {
                try {
                    i = enu.nextRecordId();
                    if (i == 1) {
                        url = new String(rms.getRecord(i));
                    } else if (i == 2) {
                        xcblength = bytesToInt(rms.getRecord(i));
                    }
                } catch (InvalidRecordIDException e) {
                    e.printStackTrace();
                }
            }
        }
        return url;
    }
}

posted on 2010-02-25 14:58 骑猪闯天下 阅读(342) 评论(0)  编辑  收藏


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