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)); V'c9DoSRI\
} qA9*t
for(int i=0;i<nEndPos.length-1;i++) GW'=/ z7
{ FU!U{qDI
nEndPos = nStartPos[i+1]; NF0IF#;a
} RUf,)]Vvk
nEndPos[nEndPos.length-1] = nFileLength; g-mK(kY4p
} y[qW>
} 2t1WbP1
=N<Hc:<t4
vb: '%^v
//启动子线程 ;5my(J*b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [rTV)JsTb
for(int i=0;i<nStartPos.length;i++) \yb^%$hZ0
{ }n=Tw92g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )_+"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *bn9j>|iv
nStartPos,nEndPos,i); PNT.9 *d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @`}'P115@
fileSplitterFetch.start(); {eIE|
} N<Bi.\XC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1|/2%IDUI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WSDNTfpI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )%X\5]w`
nEndPos = " + nFileLength); ;}f%bE
// fileSplitterFetch[nPos.length-1].start(); ZeWHSU
p: sn>Y
Yc:b:\0}F6
//等待子线程结束 A40 -])'!
//int count = 0; rC_K L
//是否结束while循环 RfN5X}&A
boolean breakWhile = false; XIBw&mWf
v8*ZwF
A6iyJFmD
while(!bStop) g?j"d{.9t
{ <py~(q
write_nPos(); q>Px
Utility.sleep(500); 4 CX*,7LZ
breakWhile = true; lBQ|=
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Syp|s3u;
for(int i=0;i<nStartPos.length;i++) 2"<}9A<Xs
{ uO[4 WZ
if(!fileSplitterFetch.bDownOver) \vQ_:-A
{ 7UQD02
breakWhile = false; Crpkq/M
break; L@a-"(TN+
} 7Fy^K;V"
} Q7=J[,V:2
if(breakWhile) 9\Xl3j!
break; C 2oll-kN
r{%NMj
&`>*3m(
//count++; KL5rF,DME
//if(count>4) uT-WQ/id
// siteStop(); lq.0?(
} Q&QR{?PMD
gLpWfT29V
`=-}S+
System.err.println("文件下载结束！"); ;F5B)&/B
} cK-!Evv
catch(Exception e){e.printStackTrace ();} pY8+;w EI
} W_sDF; JP
Ab_aB+g ]
(Nik(Oyj"
//获得文件长度 >F-J}P
public long getFileSize() dk(-yv'
{ uxh4nyE
int nFileLength = -1; ;U7\pc;S
try{ ' >\*
URL url = new URL(siteInfoBean.getSSiteURL()); [dzb{M6_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b7>;UX
httpConnection.setRequestProperty("User-Agent","NetFox"); e#zGLxa
s?`)[K'-
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int responseCode=httpConnection.getResponseCode(); Nc"h8p?
if(responseCode>=400) ;<&s_C3
{ jG.*tuf
processErrorCode(responseCode); 10[~ki-1;
return -2; //-2 represent access is error \C<rg|
} U-lN_?
G3U+BC23E
W6_3f-4g
String sHeader; <0kRky$
kb%W3c9HO
pt0H*quwI
for(int i=1;;i++) oOUVU}H
{ hD$U8~zK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r{<u\>6X>P
//Utility.log(in.readLine()); a"&Z!A:Z=
sHeader=httpConnection.getHeaderFieldKey(i); v5 9>
if(sHeader!=null) lO9>?y8.y
{ '[juPI(!
if(sHeader.equals("Content-Length")) uj:w^t ][
{ @+{S-iD"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A?7%q^;E
break; a)TNVm^
} qC6Q5F
} aIfog+Lp
else @DUdgPA
break; #dl8+
} 96PVn
} vEgJmHv;
catch(IOException e){e.printStackTrace ();} vj_oMmjKw
catch(Exception e){e.printStackTrace ();} 8n73MF
.xk<7^ZD
/f6]XP\'`+
Utility.log(nFileLength); FVD}9ia
|Ji?p>\~
Wh<lmC50(
return nFileLength; wG|3 iFK
} MkYem6
Xt7'clr
Sm1bDa\!=
//保存下载信息（文件指针位置） DRzpV6s
private void write_nPos() DQ9s57VxC!
{ K9P"ncMt
try{ nAX|=qp#
output = new DataOutputStream(new FileOutputStream(tmpFile)); M"FAUqz`
output.writeInt(nStartPos.length); CVUJ(D&Q
for(int i=0;i<nStartPos.length;i++) 5m bs0GL
{ KW;xlJz(j
// output.writeLong(nPos); 2h:f6=)r/u
output.writeLong(fileSplitterFetch.nStartPos); OcH-`A
output.writeLong(fileSplitterFetch.nEndPos); bFVdv&
} q#778
output.close(); '^J/aV
} k}O|4*.BT
catch(IOException e){e.printStackTrace ();} wYxizNv,
catch(Exception e){e.printStackTrace ();} I^wj7cFo5
} QP;b\11m
Mu(Y6
FlgB-qR]<n
//读取保存的下载信息（文件指针位置） QbNv+Eu5
private void read_nPos() "TV.$s$.
{ A,og9<+j-
try{ 'wZy: c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g:6yvEu$ -
int nCount = input.readInt(); A8RT3OiXA
nStartPos = new long[nCount]; czb%%:EJs|
nEndPos = new long[nCount]; Pz)QOrrG~
for(int i=0;i<nStartPos.length;i++) ."^dJ |fN
{ m@Nx`aS?
nStartPos = input.readLong(); 0!VLPA:
nEndPos = input.readLong(); EUn"x'
} %zD-gw>
input.close(); Gzfb|9,q
} xWwPrd
catch(IOException e){e.printStackTrace ();} }ri*e2y)
catch(Exception e){e.printStackTrace ();} ]EcZ|c7o9y
} nSow$6T_
~ghz%${`
Q)@1:(V/
private void processErrorCode(int nErrorCode) qN0#=X
{ [s34N+vU
System.err.println("Error Code : " + nErrorCode); E5t+;vL~
} Y) h%<J
]dK]a:S
"[?/I3{E
//停止文件下载 0C p}
public void siteStop() @r]s9~Lx9
{ MELGTP>
bStop = true; IX*S:7S[
for(int i=0;i<nStartPos.length;i++) Fp6Y Y
fileSplitterFetch.splitterStop(); PJYA5"}W
/T(\}Z
G}-.xj]
} .fsk DW
} eq+o_R}CS
//负责部分文件的抓取 F=om^6G%X5
**FileSplitterFetch.java p<zXuocQ
*/ |Hm'.-
package NetFox; Q kZM(pG
]18ygqt
`I>K?
import java.io.*; :|M/+XPu
import java.net.*; xs I/DW
DqMK[N,0
P{Z71a5
public class FileSplitterFetch extends Thread { 8$v7|S6 z
$048y X 7M
oyt//SE
String sURL; //File URL tvOAN|+F
long nStartPos; //File Snippet Start Position @."o:K
long nEndPos; //File Snippet End Position .lBY"W&{
int nThreadID; //Thread's ID 6}T%m?/}
boolean bDownOver = false; //Downing is over 6XAr8mw9
boolean bStop = false; //Stop identical |{PJT#W%
FileAccessI fileAccessI = null; //File Access interface `zp2;]W
rH9}nL
:2pBv#\"qk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p},Fwbl
{ !ix<|F5
this.sURL = sURL; ow_y
this.nStartPos = nStart; S@g/Tn
this.nEndPos = nEnd; <gdgcvd
nThreadID = id; eM+;x\jo?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >NRz*h#
} n6-Ic',;
'98h<(@]
7F(F.ut
public void run() -?nT mzRc
{ &fSc{/
while(nStartPos < nEndPos && !bStop) n]DNxC@b
{ H~|%vjH
@7s,|\
-+rF]|Wi
try{ 3Y{)(%I
URL url = new URL(sURL); b3b~T]]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fHd!/%iG
httpConnection.setRequestProperty("User-Agent","NetFox"); 8RAeJ~e
String sProperty = "bytes="+nStartPos+"-"; 7_40_kwJi
httpConnection.setRequestProperty("RANGE",sProperty); [-t> G!)
Utility.log(sProperty); bkwa{V
[Hj'nA^
9V;$v
InputStream input = httpConnection.getInputStream(); ;:4P'FWm^
//logResponseHead(httpConnection); N 2"3~ #
0R}Sw[M.
vA;F]epr!
byte[] b = new byte[1024]; 2]} Uov
int nRead; akhL\-d)al
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V`\f+Uu
{ 9*|3E"Vr
nStartPos += fileAccessI.write(b,0,nRead); w2d]96*kQe
//if(nThreadID == 1) So=nB} b[?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `_1(Q9Q
} Z|(c(H2
f5aF6FBH
VS9]po>=
Utility.log("Thread " + nThreadID + " is over!"); '^Utbp2<
bDownOver = true; 4`6c28K0?
//nPos = fileAccessI.write (b,0,nRead); 3_MS'&M
} +lW}ixt
catch(Exception e){e.printStackTrace ();} {@V3?pG?p
} lU$4NUwM
} X&(ERY,h
(]Ye[j^"7
Q)Iv_N/
//打印回应的头信息 2]D$|M?$~
public void logResponseHead(HttpURLConnection con) qB F!b0lr
{ )[^y t0%
for(int i=1;;i++) abo>_"9-
{ )Ig+uDGk
String header=con.getHeaderFieldKey(i); :4ja@~
if(header!=null) {^cF(7p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I f3{E
Utility.log(header+" : "+con.getHeaderField(header)); Or+*q91j
else #Pu@Wx
break; u m:0y,
} *:\:5*SY
} F#1 Kk#t
1l+kO,X]
{}_Nep/;
public void splitterStop() 7}ws |4Y
{ 3vdu;W=Sz
bStop = true; I7dm \|#
} +UK%t>E8
]<kupaRQ
RCBf;$O
} |rHG%VnBH
=.36y9Mfo
UzgA26;
/* [DZqCo
**FileAccess.java 7R9nMGJ@
*//文件访问(定位，写) /l,+oG%\
package NetFox; ietRr!$.
import java.io.*; )MWUS;O<
~u /aOd
s\'y-UITi1
public class FileAccessI implements Serializable{ e1 x^PT
qH#r-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R_1)mPQ^P
RandomAccessFile oSavedFile; v7i^O`{eD?
long nPos; ~+O`9&
4\LZD{
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public FileAccessI() throws IOException TB7>s~)47E
{ &?.n2+T+ =
this("",0); )0#j\B
} {=UFk-$=
Y5dD|]F|
D \N \BD
public FileAccessI(String sName,long nPos) throws IOException Bo`Tl1K#
{ _u&>&,:q
oSavedFile = new RandomAccessFile(sName,"rw"); GX4QaT%
this.nPos = nPos; ?y~TCqV
oSavedFile.seek(nPos); O: ,$%
} 0b/ir2
LHh5 v"zjG
)~ 0}Et l
public synchronized int write(byte[] b,int nStart,int nLen) %35L=d[
{ I2f?xJ2/Z
int n = -1; #6Jc}g<?g
try{ 9G0D3F
oSavedFile.write(b,nStart,nLen); fUC9-?(K
n = nLen; .VT;H1#
} 1/B]TT
catch(IOException e) wfgqgPo!v
{ T~BA)![
e.printStackTrace (); 2w+U$6e C
} Cye T]y
%2f//SZ:
pSHSgd~&
return n; ^ eQFg>
} $ +;+:K
!p9)CjQ"
A{# Nwd>
} x2co>.i
? B@&#E!/f
~9\$5n)a
/* nVE9^')8V
**SiteInfoBean.java &-%>qB|*
*/ ~ 3^='o
package NetFox; 'Gx$Bj
8)N@qUV
B z^|SkEit
public class SiteInfoBean { F]UQuOR)
QT! 4[,4
J'b<z.OW
private String sSiteURL; //Site's URL }pVTTs`
private String sFilePath; //Saved File's Path k|xtrW`qo;
private String sFileName; //Saved File's Name /kgeV4]zR
private int nSplitter; //Count of Splited Downloading File !gF9k8\Yr$
ndink$
%f j+70
public SiteInfoBean() O}Hf62"
{//nSplitter的缺省值为5 X&M4MuL
//default value of nSplitter is 5 fmfTSN(Q~`
this("","","",5); pd3,pQ
} sV/l5]b]
mMSh2B
.f:n\eT):
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "9IYB)Js
{ ('O}&F1
sSiteURL= sURL; nOb?-rR
sFilePath = sPath; *4S-z&,.c
sFileName = sName; Df4+^B,1
this.nSplitter = nSpiltter; hoM|P8 }rh
RBwO+J53y
FdzNE
} W#'c5:m 4
iYJZvN
iCj2"T4TN
public String getSSiteURL() MP^ d}FL
{ a,|?5j9,P
return sSiteURL; ?m7:if+y
} T f4tj!t-
POAw M
ht=P\E
public void setSSiteURL(String value) {D`'0Z1"
{ ~j>D=!
sSiteURL = value; Z(u5$<up
} c$:1:B9\
<IJu7t>
xYfD()w<I
public String getSFilePath() GOT1@.Y
{ M;w?[yEZ
return sFilePath; 4dawg8K`9
} _;1}x%4v
OFk8>"|
?S Z1`.S
public void setSFilePath(String value) ]:(W_qEA
{ mYxyWB
sFilePath = value; m8R9{LC
} \Q~8?p+
^EELaG
fu[K".
public String getSFileName() &;i "P
{ %" D%:
return sFileName; 0NDftcB]
} m)v''`9LU
[AU II*:}
2P#=a?~[
public void setSFileName(String value) @"-</x3o
{ d}'U?6ob
sFileName = value; 1Xu?(2;NF
} );V2?G`/
S! Rc|6y%
fq )vK
public int getNSplitter() 'e)^m}:?D
{ NLS"eDm
return nSplitter; fKH7xu!V4+
} =m89z}Ot
?BA]7M(,4
$+JS&k/'m
public void setNSplitter(int nCount) {n#k,b&9B
{ kOOGw:/
nSplitter = nCount; Q?b14]6im
} N;Dp~(1 J1
} +4;uF]T
$YxBE`)d-
?eH&'m}-
/* +gd4\ZG
**Utility.java Hy.AyU|L
*/ [^CV>RuO
package NetFox; aj8A8ma*}
ca i<,3H
32DbNEk
public class Utility { -fhN"B)
8Jf.ECQT
1"Z@Q`}
public Utility() **9x?s
{ n0Y+b[+wj
pl@O N"=[
2M#M"LHo
} Q!- 0xlx
Jk@]tAwoM
//线程睡眠 0a8/B>
public static void sleep(int nSecond) XO#/Fv!
{ `&\Q +W
try{ theZ]5_C
Thread.sleep(nSecond); ojYbR<jn9
} Xq'cA9v=$J
catch(Exception e) `E+Jnu,jC
{ QaUm1i#
e.printStackTrace (); D\IjyZ-O
} SJD@&m%?[
} mc=LP>uoS
DPi_O{W>
//日志 !.2<| 24
public static void log(String sMsg) ]7-&V-Ct*
{ Qt_dEl
System.err.println(sMsg); l/;X?g5+
} B8E'ddUw
"KcA
n>@oBG)!
public static void log(int sMsg) z/i+EE
{ 21k5I #U
System.err.println(sMsg); ga?*DI8w
} d%l{V6
} _|h8q-[3
G\|,5HED
&zs'/xv]
/* U qG .:@T
**TestMethod.java {vAE:W.s
*/ Gt9&)/#
package NetFox; IV\J3N^
>S$Z
ss;R8:5
public class TestMethod { d,Y_GCZ7|W
Y*mbjyt[?X
A?Bif;
public TestMethod() ECv)v
{ ///xx/weblogic60b2_win.exe 2]%h$f+
try{ !i=nSqW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lu Q~YjH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mq';S^
SiteFileFetch fileFetch = new SiteFileFetch(bean); jxYc2
fileFetch.start(); (O0Urm
} d)~Fmi;
catch(Exception e){e.printStackTrace ();} apE
}fp-5
CI3XzH\IX*
} `/Y{ l
JN7k2]{
N},n `Yl.
public static void main(String[] args) &89oO@5
{ 0uBl>A7qhn
new TestMethod(); Tw +
} q^6+!&"
} T|tOTk
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