http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); VMH^jCFp
} lb\VQZp!y
for(int i=0;i<nEndPos.length-1;i++) .JX9(#Uk
{ DhD^w;f]
nEndPos = nStartPos[i+1]; D";@)\jN
} ^]MLEr!S
nEndPos[nEndPos.length-1] = nFileLength; R'Uf#.
} fi [4F
} |H.ARLS
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//启动子线程 pv]" 2'aQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i>e?$H,/
for(int i=0;i<nStartPos.length;i++) %S/?Ci
{ 1P?|.W_^1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z}S7%m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H{hzw&dZ<P
nStartPos,nEndPos,i); YO9;NA{sH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _$i)bJ
fileSplitterFetch.start(); &yG5w4<
} EYA=fU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '}$$0S.DC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8p]9A,Uq&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9;NXzO27
nEndPos = " + nFileLength); 0ZJj5<U
// fileSplitterFetch[nPos.length-1].start(); ($-m}UF\/
2P^x'I
iFnD`l6)
//等待子线程结束 BhhFij4
//int count = 0; xZA.<Yd^r
//是否结束while循环 1Eb2X}XC
boolean breakWhile = false; b8E7/~<z3
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while(!bStop) e, fZ>EJ
{ sLUOs]cj
write_nPos(); +t3o5&
Utility.sleep(500); ~*x 2IPiH
breakWhile = true; 1!NrndJI
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for(int i=0;i<nStartPos.length;i++) gloJ;dEB
{ d/!\iLF
if(!fileSplitterFetch.bDownOver) mM:%-I\$
{ &x7iEbRs
breakWhile = false; F^81?Fi.
break; 1)5$,+~lL
} qA"BoSw4
} O]'2<;
if(breakWhile) RL3*fRlb
break; W4UK?#S+
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sNM ]bei
//count++; t&Q(8Hz
//if(count>4) No`*->R
// siteStop(); hZlHY9[t?
} B<i(Y1n[
#p"$%f5Q_
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System.err.println("文件下载结束！"); d0-4KN2
} *2pf>UzL
catch(Exception e){e.printStackTrace ();} 4:-x!lt
} 7ug"SV6Hb
)/)[}wN;j
x"!`JDsS
//获得文件长度 BoxtP<C"
public long getFileSize() GUZ.Pw
{ m'QG{f
int nFileLength = -1; u /]P
try{ H]7bqr
URL url = new URL(siteInfoBean.getSSiteURL()); sO}CXItC+j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KA{&NFx
httpConnection.setRequestProperty("User-Agent","NetFox"); i&?\Pp;5-j
c g)>A
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int responseCode=httpConnection.getResponseCode(); QO^V@"N
if(responseCode>=400) lX.-qCV"B
{ ,J,Rup">h
processErrorCode(responseCode); NGJst_
return -2; //-2 represent access is error (T%?@'\
} ,H%[R+)
{2YqEX-I*
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String sHeader; }0tHzw=#%e
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for(int i=1;;i++) *CPpU|
{ 8|^&~Rl4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qoOwR[NDcq
//Utility.log(in.readLine()); qYJ<I'Ux O
sHeader=httpConnection.getHeaderFieldKey(i); 3n)$\aBE
if(sHeader!=null) / g{8
{ _VVq&t}
if(sHeader.equals("Content-Length")) r-go921
{ 6<T:B[a-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Il Qk W<
break; ;S \s&.u
} /_})7I52
} 0KTO)K
else @_?2iN?4Z
break; ar#73f
} )z\#
} c BZ,"kp-
catch(IOException e){e.printStackTrace ();} Xdx8HB@L
catch(Exception e){e.printStackTrace ();} \Oq8kJ=
*hru);OJr
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Utility.log(nFileLength); ~TsRUT
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return nFileLength; ox%j_P9@:
} /,\U*'-
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yQMwt|C4
//保存下载信息（文件指针位置） !+A%`m
private void write_nPos() )obgEJ7Y`l
{ H`'a|Y
try{ fLqjBG]<
output = new DataOutputStream(new FileOutputStream(tmpFile)); T.3{}230<
output.writeInt(nStartPos.length); tsL ; wT_
for(int i=0;i<nStartPos.length;i++) 8["%e#%`$
{ ^8_yJ=~V
// output.writeLong(nPos); ]XbMqHGS
output.writeLong(fileSplitterFetch.nStartPos); i@.Tv.NZ
output.writeLong(fileSplitterFetch.nEndPos); 8toOdh
} sv?Fx;d
output.close(); %~x?C4L8
} ah hl
catch(IOException e){e.printStackTrace ();} "~0`4lo:Xo
catch(Exception e){e.printStackTrace ();} "+T`{$Z=C
} '?| 1\j
+Wg/O -
>h)kbsSU0z
//读取保存的下载信息（文件指针位置） bXvO+I<
private void read_nPos() `-.2Z 0
{ @fYVlHT%E
try{ uxB)dS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [#mkTY
int nCount = input.readInt(); N|$9v{ j_
nStartPos = new long[nCount]; ~HhB@G!3
nEndPos = new long[nCount]; #Zw:&' QB
for(int i=0;i<nStartPos.length;i++) $BMXjXd}
{ :MY=Q]l
nStartPos = input.readLong(); :>JfBJ]|
nEndPos = input.readLong(); P*BRebL:
} n)"JMzjQ<
input.close(); -f&vH_eK
} !5(DU~S*@S
catch(IOException e){e.printStackTrace ();} l[c '%M|N
catch(Exception e){e.printStackTrace ();} 0t%]z!
} e}1Q+h\
w(&EZDe
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private void processErrorCode(int nErrorCode) " Q?~LB
{ wR@>U.XT@
System.err.println("Error Code : " + nErrorCode); >fzyD(>
} %L*EB;nK
~Ym_ {
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//停止文件下载 $uDgBZA\
public void siteStop() Qgj# k
{ / Qd` ?
bStop = true; U,#x\[3!Jt
for(int i=0;i<nStartPos.length;i++) lQ`=PFh
fileSplitterFetch.splitterStop(); '0+~]4&}q
pQBn8H|Y
#| _VN %!
} n}.e(z_"
} Hs'~)T
//负责部分文件的抓取 nH?6o#]N
**FileSplitterFetch.java XJ\R'?j
*/ DOJydYds
package NetFox; 9>w~B|/
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import java.io.*; olv?$]
import java.net.*; o& FOp'
rL1yq|]I
HvG %##
public class FileSplitterFetch extends Thread { '~&W'='b;
@6yc^DAA
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String sURL; //File URL hg" i;I
long nStartPos; //File Snippet Start Position Pgr2S I
long nEndPos; //File Snippet End Position (T#$0RFq
int nThreadID; //Thread's ID qisvGHo
boolean bDownOver = false; //Downing is over Q}@t'
boolean bStop = false; //Stop identical xyL)'C
FileAccessI fileAccessI = null; //File Access interface B#S8j18M
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Of6Ij?
{ * )<+u~
this.sURL = sURL; 8F8?1
this.nStartPos = nStart; o'$"MC+
this.nEndPos = nEnd; ,~naKd.ZY
nThreadID = id; g=$U&Hgs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8xO
} !2KQi=Ng
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public void run() :TU|:2+
{ ZQE1]ht
while(nStartPos < nEndPos && !bStop) sh_;98^
{ VQHB}Y@^
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try{ q k^FyZ<
URL url = new URL(sURL); I;t@wbY,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tJ6@Ot
httpConnection.setRequestProperty("User-Agent","NetFox"); '-%1ILK$3r
String sProperty = "bytes="+nStartPos+"-"; .@,t}:lD
httpConnection.setRequestProperty("RANGE",sProperty); d#0:U Y%~
Utility.log(sProperty); z9ADF(J?0'
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InputStream input = httpConnection.getInputStream(); )*]A$\Oc[
//logResponseHead(httpConnection); R7Y_ 7@p
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byte[] b = new byte[1024]; US ALoe
int nRead; r& a[?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G(a5@9F
{ %i9 e<.Ot
nStartPos += fileAccessI.write(b,0,nRead); |MZ1j(_
//if(nThreadID == 1) T ?[28|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1 jidBzu<
} BI`)P+K2
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,~d0R4)
Utility.log("Thread " + nThreadID + " is over!"); N@c GjpQ
bDownOver = true; +-<G(^
//nPos = fileAccessI.write (b,0,nRead); <}RI<96
} n>ui'}L
catch(Exception e){e.printStackTrace ();} TF/NA\0c$
} v@Uk% O/
} }pMVl
VC88re`
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//打印回应的头信息 >)ekb7
public void logResponseHead(HttpURLConnection con) q~R8<G%YK
{ OS,!`8cw
for(int i=1;;i++) vdq=F|&
{ \l:R]:w;ZI
String header=con.getHeaderFieldKey(i); <==uK>pET
if(header!=null) :'DyZy2Fd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {}YA7M:L
Utility.log(header+" : "+con.getHeaderField(header)); Da(k>vR@4
else TRm#H$
break; ZW [&7[4
} &THtQ1D
} .#QE*<T)]
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public void splitterStop() 7~XC_Yc1
{ Z`tmuu
bStop = true; :RnUNz
} {6ZSf[Y6B
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} "] V\Y!
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'."_TEIF
/* nEsD+}E?
**FileAccess.java zo ?RFn
*//文件访问(定位，写) Y#9W]78He
package NetFox; n|{K_! f
import java.io.*; =1Sny7G
VP#KoX85
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public class FileAccessI implements Serializable{ H@uu;:l<7A
x2B8G;6u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `}?;Ow&2CY
RandomAccessFile oSavedFile; ,m#
long nPos; ni?k' \\
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public FileAccessI() throws IOException dkw.o.e
{ '.bf88D
this("",0); TTVmm{6
} L(;$(k-/(
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public FileAccessI(String sName,long nPos) throws IOException Ok_}d&A
{ w#b@6d
oSavedFile = new RandomAccessFile(sName,"rw"); <r#FI8P;X
this.nPos = nPos; _2jL]mB
oSavedFile.seek(nPos); PB@IPnB-
} VgNB^w
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public synchronized int write(byte[] b,int nStart,int nLen) ?/o 8f7Z
{ w,p'$WC*
int n = -1; FLWVI4*
try{ gQPw+0w
oSavedFile.write(b,nStart,nLen); ;?/5Mr
n = nLen; Y$ jX
} I<#X#_YP
catch(IOException e) eNd&47lJ
{ qzZ/%{Ak
e.printStackTrace (); t<UJR*R=L
} V?M(exN
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return n; &4:R(]|
} M(a%Qk?]/
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} N9!L8BBaK
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zGtJ@HbB
/* _Tj&gyS
**SiteInfoBean.java O>h`
*/ I0+6p8,
package NetFox; ]Ucw&B*@
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public class SiteInfoBean { 5GM-*Ak@
wyy 1M+
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private String sSiteURL; //Site's URL D6L+mTN
private String sFilePath; //Saved File's Path 9O 'j+?(`@
private String sFileName; //Saved File's Name >:-e
private int nSplitter; //Count of Splited Downloading File HEVjK$
"Wj{+|f
%6 *c40
public SiteInfoBean() S"&Gutu3o
{//nSplitter的缺省值为5 >`AK'K8{M
//default value of nSplitter is 5 PuJ3#H T
this("","","",5); %+l95Dv1
} a^%)6E.[,
p3A9<g
LFax$CZc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3Z?ornS
{ 5mZ2CDV
sSiteURL= sURL; TLsF c^X
sFilePath = sPath; {5Bj*m5
sFileName = sName; q}t]lD %C
this.nSplitter = nSpiltter; GTR*3,rw
h[>pC"s?K
KA?}o^-F
} 86{>X5+
j,i9,oF6]
>Hnm.?-AWl
public String getSSiteURL() V[(fE=cIN~
{ 'W(u.
return sSiteURL; xq((]5Py
} GURiW42
~]-n%J$q
M G$+Blw>
public void setSSiteURL(String value) U 3< 3T
{ T_S3_-|{==
sSiteURL = value; v*!N}1+J
} K) }1;
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public String getSFilePath() ye.6tlW
{ oks;G([
return sFilePath; @%,~5{Ir
} on7 n4
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public void setSFilePath(String value) RHFRN&RU$
{ H0s*Lb
sFilePath = value; %'1iT!g8
} KVOV<uDCj
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public String getSFileName() &\9%;k
{ f- XUto
return sFileName; &<;T$Y
} vqN/crJ@
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public void setSFileName(String value) DT`HS/~fH
{ ;}SGJ7
sFileName = value; M*0^<e~]F
} q? ">
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public int getNSplitter() PRU&y/zZmG
{ -W9DH^EL<
return nSplitter; Nud =K'P=
} 1\fx57a\
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public void setNSplitter(int nCount) He=C\"
{ J:Fq ip
nSplitter = nCount; qGA|.I9,
} f5*qlQJFz\
} ycBgr,Ynu<
h}a}HabA
RFRXOyGz$
/* ?xqS#^Z
**Utility.java !+eU
*/ !K(
package NetFox; Da 7(jA+
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public class Utility { 7K.75%}
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(B4)L%
public Utility() i?!9%U!z4
{ b,+Sa\j)(
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1Rd|P<y
} -rU_bnm
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//线程睡眠 Z5'^81m$o
public static void sleep(int nSecond) ~ L4NK#
{ 1Of(O!
try{ B<I(t"s
Thread.sleep(nSecond); hZ1enej)
} lNxP
catch(Exception e) .6`r`|=
{ [ iTP:8
e.printStackTrace (); <OEIG0
} 4,;*sc6*
} LVg#E*J
/[_aK0U3
//日志 )IcSdS0@M
public static void log(String sMsg) 5! );4+
{ =;-C;gn:w
System.err.println(sMsg); =Smd/'`_
} {j$2=0Cec
i975)_X(
$=.%IJ_MAz
public static void log(int sMsg) UK,bfLPt~
{ ?L0;, \-t
System.err.println(sMsg); ntH`\ )xi
} F2 B(PGa7
} 0 8)f
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/* _{`Z?lt
**TestMethod.java >s5}pkAv|e
*/ =J1V?x=l@
package NetFox; he~8V.$
$\ZWQct
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public class TestMethod { Q`*U U82!
<5G(Y#s/?
R*pPUw\yn
public TestMethod() Xb:* KeZq
{ ///xx/weblogic60b2_win.exe kKlNhP(
try{ OvT[JpV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :lXY% [!6P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~TH4='4W3
SiteFileFetch fileFetch = new SiteFileFetch(bean); MDytA0M
fileFetch.start(); MxpAh<u!vF
} n>pJ/l%`
catch(Exception e){e.printStackTrace ();} E@C.}37R
:oy2mi;
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} We$ n
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public static void main(String[] args) wKi#5k2
{ ^S`hKv&87
new TestMethod(); 2n3&uvf'TL
} f5F-h0HF`[
} bz>\n"'
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