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)); ( ALsc@K
} d$v{oC}
for(int i=0;i<nEndPos.length-1;i++) 8:}$L)[V
{ ]`eJSk.
nEndPos = nStartPos[i+1]; N"/be
} =N{-lyr)
nEndPos[nEndPos.length-1] = nFileLength; H9rZWc"*
} qN6GLx%
} Oa-~}hN
lK #~lC
2%t!3F:
//启动子线程 9XW[NY#)#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fFd"21>
for(int i=0;i<nStartPos.length;i++) a|@1RH>7H
{ LrnE6U9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D}EH9d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \t]aBT,
nStartPos,nEndPos,i); "'mr0G9X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _tVrLb7`s
fileSplitterFetch.start(); ]=m0@JTbG
} +ZeK,Y+Xy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5c3&4,,eR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "aeKrMgc6V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0vdnM8N2
nEndPos = " + nFileLength); *Y- rEF>
// fileSplitterFetch[nPos.length-1].start(); j:'!P<#
r2>y !Q?
\DRYqLT`
//等待子线程结束 F` ]s
//int count = 0; Xc7Qu?}
//是否结束while循环 p|R]/C0f
boolean breakWhile = false; Rj{D#5
QD*(wj
(1?k_!)T
while(!bStop) CiC@Z,ud`
{ ,v*<yz/
write_nPos(); ED R*1!d
Utility.sleep(500); d)jX%Z$LC
breakWhile = true; o$bD?Zn
dG'5: ,n/
C$fQ[@
for(int i=0;i<nStartPos.length;i++) qAR}D~t
{ J`{HMv
if(!fileSplitterFetch.bDownOver) /A/k13 J
{ Q OP8{~O
breakWhile = false; Se&%Dr3Nv
break; iC\t@BVS
} )ia$pes
} d#wK
if(breakWhile) 8sxH)"S
break; ?u /i8
Ue]GHJ2
f=*xdOB3
//count++; ]mmL8%B@_
//if(count>4) NI% ()
// siteStop(); @awN*mO
} 0qMf6
OgBZoTT
E[E[Za^Y
System.err.println("文件下载结束！"); RVb}R<yU+
} Z )dz
catch(Exception e){e.printStackTrace ();} ZVmgQ7m
} OQZ\/~o 5
5T;,wQ<
cE0Kvqe`
//获得文件长度 Ok2>%e
public long getFileSize() >QM$ NIf@
{ wXxk+DV@
int nFileLength = -1; ~",,&>#[K
try{ )t$|'c}
URL url = new URL(siteInfoBean.getSSiteURL()); dsJHhsu6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Uw5`zl
httpConnection.setRequestProperty("User-Agent","NetFox"); ^YG.eT6iG
Ws(#ThA
3Q"4-pd
int responseCode=httpConnection.getResponseCode(); S[W|=(f9
if(responseCode>=400) 1ssEJ;#s
{ r)SwV!b
processErrorCode(responseCode); /R44x\nhr
return -2; //-2 represent access is error L(!mm
} ^atBf![
27Ve$Q8]v
/IN/SZx
String sHeader; sd~T
=!%+ sem
I7nZ9n|KU
for(int i=1;;i++) Pkw` o #
{ {|J'd+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E64d6z^7u
//Utility.log(in.readLine()); /^z5;aG
sHeader=httpConnection.getHeaderFieldKey(i); wFJ?u?b0Q
if(sHeader!=null) lfp'D+#p{
{ .2 /$ !'E
if(sHeader.equals("Content-Length")) 4aQb+t,
{ v/yt C/WH"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R83Me#&
break; p4OiCAW;
} ndIU0kq3
} ;eRYgC
else ^.9I[Umua
break; YSE6PG
} 7!E?(3$#"
} 9}2E+
catch(IOException e){e.printStackTrace ();} Qm X(s
catch(Exception e){e.printStackTrace ();} N yK7TKui
s~(iB{-
@gZ<!g/vza
Utility.log(nFileLength); CS*wvn;.
p}'uCT ga
2nRL;[L*.
return nFileLength; E5<}7Pt
} VfiMR%i}
NN9`jP2
H `V3oS~}
//保存下载信息（文件指针位置） Gq/f|43}@O
private void write_nPos() @ 0RB.-
{ zU9G:jH
try{ kG7q4jFwP
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z)zWfv}
output.writeInt(nStartPos.length); ~agzp`!M
for(int i=0;i<nStartPos.length;i++) ^{T3lQvt
{ )c#m<_^
// output.writeLong(nPos); ]jz%])SzH
output.writeLong(fileSplitterFetch.nStartPos); [1Yx#t
output.writeLong(fileSplitterFetch.nEndPos); 9s-op:5
} Z;{3RWV
output.close(); t-$R)vZ}M
} #~r+
catch(IOException e){e.printStackTrace ();} jyt#C7mj-A
catch(Exception e){e.printStackTrace ();} VzR(OB
} *$Df)iI6
*kXSl73 k
AqKl}8
//读取保存的下载信息（文件指针位置） q1Si*?2W
private void read_nPos() s}d1 k
{ S3=M k~_&
try{ H3"[zg9L:a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n#G I& U
int nCount = input.readInt(); o[bG(qHZ
nStartPos = new long[nCount]; wr=h=vXU[
nEndPos = new long[nCount]; zOpl#%"
for(int i=0;i<nStartPos.length;i++) L$GhM!c
{ yVyh'd:Ik
nStartPos = input.readLong(); uLsGb=m%b
nEndPos = input.readLong(); `A)9
} IwIk;pB O
input.close(); .Y%)&
} nL+*-R!R
catch(IOException e){e.printStackTrace ();} Hb3+$vJ^
catch(Exception e){e.printStackTrace ();} Q)c$^YsI
} e'oM%G[
:4"SJ
+b.qzgH>r
private void processErrorCode(int nErrorCode) VJX{2$L
{ XB)e;R
System.err.println("Error Code : " + nErrorCode); gOI#$-L
} `MgR/@%hr
`CI9~h@k
\guZc}V]:\
//停止文件下载 .[hQ#3)W
public void siteStop() %:n1S]Vr
{ mN^92@eebC
bStop = true; {6v|d{V+e
for(int i=0;i<nStartPos.length;i++) /vl]Oa&U
fileSplitterFetch.splitterStop(); !<!sB)
kSH3)CC P
b'^OW
} ${#5$U+kI
} ^j?\_r'j
//负责部分文件的抓取 }ZEh^zdz8
**FileSplitterFetch.java q!k F
*/ AF1";duA
package NetFox; <R7*00
`)F lb|da
eB78z@
import java.io.*; @.gT&Hq
import java.net.*; _F^k>Lq&d
_7YAF,@vT
C|Bk'<MI
public class FileSplitterFetch extends Thread { zYdSg<[^
~F*pV*
sB_o HUMH6
String sURL; //File URL !ZbNW4rIP
long nStartPos; //File Snippet Start Position U`JzE"ps]
long nEndPos; //File Snippet End Position +(5H$O{h
int nThreadID; //Thread's ID owTW_V
boolean bDownOver = false; //Downing is over ?#xNz=V
boolean bStop = false; //Stop identical cI4%zeR
FileAccessI fileAccessI = null; //File Access interface _=jc%@]1y
hi>Ii2T
. ({aPtSt!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l^ni"X
{ |EaGKC(
this.sURL = sURL; `LnLd;Z
this.nStartPos = nStart; V-CPq
this.nEndPos = nEnd; {nT !|S)$
nThreadID = id; -[s*R%w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0k>NuIIP
} J={$q1@lq
-9/YS
9U6y<X
public void run() ;h_"5/#
{ mSAuS)YD
while(nStartPos < nEndPos && !bStop) 8Uvf9,I'
{ ,JT|E~P?8
@QtJ/("&WC
/a6\G.C5
try{ ?rWqFM:hb
URL url = new URL(sURL); !h7`W*::
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ly\$?3h
httpConnection.setRequestProperty("User-Agent","NetFox"); P"_x/C(]@J
String sProperty = "bytes="+nStartPos+"-"; &by,uVb=|{
httpConnection.setRequestProperty("RANGE",sProperty); m^h"VH,
Utility.log(sProperty); ?]f+)tCMs
(o{-1Dg)
JGSeu =)
InputStream input = httpConnection.getInputStream(); uJMF\G=nb
//logResponseHead(httpConnection); $Ha?:jSc
gE JmMh
m:/@DZ
byte[] b = new byte[1024]; "j3Yu4_ks
int nRead; '/SMqmi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SxC$EQgL
{ DTN@b!
nStartPos += fileAccessI.write(b,0,nRead); N7%Jy?-+
//if(nThreadID == 1) bXc7$5(!VB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7i~::Z <
} GY<Y,
*-Y77p7u
P$2J`b[H$
Utility.log("Thread " + nThreadID + " is over!"); 2Y&z}4'j
bDownOver = true; 8 +xLi4Pw
//nPos = fileAccessI.write (b,0,nRead); WE4:Jy
} {O#=%o[
catch(Exception e){e.printStackTrace ();} K8{j oh
} OCo=h|qBp
} b=-<4Vu*\
b^ly
TF|GGYi
//打印回应的头信息 5|xFY/%
public void logResponseHead(HttpURLConnection con) {LJwW*?
{ 9+9}^B5@A
for(int i=1;;i++) '/b,3:
{ dnNC = siY
String header=con.getHeaderFieldKey(i); d#I'9O0&
if(header!=null) k$}XZ,Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O?D*<rwD
Utility.log(header+" : "+con.getHeaderField(header)); ,Zzh.z::D
else %fh ,e5(LT
break; *FR Eh@R
} ;%]Q%7
} \Yz>=rY
=]\,I'
DkA cT[
public void splitterStop() Q0,]Q ]_
{ CCp{ZH s
bStop = true; m'r6.Hp3Ng
} +f+x3OMX3
VGM8&J{o'
h -+vM9j
} w@nN3U+
;_of'
waQNX7Xdn
/* HvK<>9
**FileAccess.java rcq(p(!
*//文件访问(定位，写) g$?B!!qT
package NetFox; s41<e"
import java.io.*; wX#=l?,K
R"!.|fH6
7&:gvhw
public class FileAccessI implements Serializable{ JE9|;A
el.;T*Wn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B~lrd#qC
RandomAccessFile oSavedFile; _,NL;66=[
long nPos; W*u Yb|0
9X@y*;w<t
zbx,qctYo$
public FileAccessI() throws IOException Yj/S(4(h?
{ #_QvnQ?I
this("",0); KZ`d3ad
} {_ww1'|A
EHcqj;@m
X;v/$=-mz
public FileAccessI(String sName,long nPos) throws IOException =:1f 0QF
{ 3kdTteyy+
oSavedFile = new RandomAccessFile(sName,"rw"); @&S4j]rq
this.nPos = nPos; r=s,Ath
oSavedFile.seek(nPos); oA"t`,3
} st|$Fu
b3H~a2"d
_|wgw^.LJ]
public synchronized int write(byte[] b,int nStart,int nLen) 37a"<
{ I^[R]Js
int n = -1; (".`#909
try{ T}$1<^NK
oSavedFile.write(b,nStart,nLen); Mm:6+
n = nLen; .O3i"X]
} pYI`5B4
catch(IOException e) MH?|>6
{ PD$ay^Y
e.printStackTrace (); V~&P<=8;Wl
} >VE,/?71@
L<J';#BD
]H[RY&GY
return n; e8a_)TU?
} xFHc+m' m~
R6h(mPYA
8PDt 7 \
} 9&g//JlD
s IY`H^
)|XmF4R
/* fR~_5pt7
**SiteInfoBean.java /wKW
*/ Aw;~b&.U{_
package NetFox; Ii,e=RG>
{|^9y]VFu
Um4 }`
public class SiteInfoBean { tUGnD<P
s59v* /
gJ+MoAM"
private String sSiteURL; //Site's URL p=coOWOQ
private String sFilePath; //Saved File's Path gvr"F
private String sFileName; //Saved File's Name +%7yJmMw
private int nSplitter; //Count of Splited Downloading File pOyM/L
*,%H1)Tj}
9 @!Og(l
public SiteInfoBean() LU?X|{z
{//nSplitter的缺省值为5 KY!
//default value of nSplitter is 5 sI@m"A
this("","","",5); ZQD_w#0j
} 0X~
TixHEhw
gkI(B2,/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mSY;hJi
{ Ss@\'K3e
sSiteURL= sURL; PQa{5"
sFilePath = sPath; KX"?3#U#Fm
sFileName = sName; RN5\,>+
this.nSplitter = nSpiltter; ]-bA{@tP.
=xSFKu*
ivb&J4?y
} 2rB$&>}T
V.XHjHT
zg.'
public String getSSiteURL() Kg VLXI6
{ oA(jtX[(
return sSiteURL; ^e"BY(
} IU{~{(p"
Tt`|26/
x4CrWm
public void setSSiteURL(String value) J*-m!0 5
{ 38L8AJqD
sSiteURL = value; o*_[3{FU
} ^W eE%"
al F*L
GLB7h9>
public String getSFilePath() 9jDV]!N4
{ +6B(LPxgP
return sFilePath; 6^H64jM
} 2IFri|;-eb
^'lx5+-
e#:.JbJ:D
public void setSFilePath(String value) UAFl+d!
{ vd|PTHV_
sFilePath = value; R61.!ql%w
} ctTg-J2.
V()s!w
<*V%!pwIG
public String getSFileName() yH;=Y1([
{ ` Xhj7%>
return sFileName; -N<s =
} ax[-907
D?44:'x+-
SpdQ<]
public void setSFileName(String value) EFW'D=&h8
{ %C" wUAY
sFileName = value; i~@e}=
} y1p^ &9U
"diF$Lj
[c+[t3dz
public int getNSplitter() "9!ln
{ 3!_y@sWx
return nSplitter; X~*1
} b6RuYwHWV0
{VE\}zKF
#Q.A)5_
public void setNSplitter(int nCount) -8-
{ x~j>Lvw L
nSplitter = nCount; s]#D;i8
} c/DB"_}!a
} 0.'$U}#b
z2vrV?:
OIGu`%~js
/* TppR \[4]
**Utility.java {f((x1{HZx
*/ gtHWd;1&f
package NetFox; v#q7hw=
-Ob'/d5&
i^eU!^KF
public class Utility { z|^:1ov,
3,DUT{2
KhIg
public Utility() }b)7gd=
{ &m&Z^CA
`wj<d>m
KC9_H>
} %JeT,{
ekND>Qjj
//线程睡眠 8iaP(*J
public static void sleep(int nSecond) ~2+J]8@I]
{ {U?/u93~
try{ hm*1w6 =
Thread.sleep(nSecond); )D\!#<#h
} X31[
catch(Exception e) |=fa`8mG
{ _CN5,mLNRk
e.printStackTrace (); Q'/v-bd?o
} /FJ )gQYA
} Aj((tMJNOw
{&nL'R
//日志 uDvZ]Q|.
public static void log(String sMsg) ~,3+]ts='\
{ =Y Je\745
System.err.println(sMsg); h}r.(MVt
} LfOXgn\
B*!{LjXV
o9&1Ct
public static void log(int sMsg) G`8i{3:
{ m%hI@'
System.err.println(sMsg); d#xi_L!
} _Cn[|E
} zO)A_s.6K
0`VA}c
Mhp6,JL
/* 3]"RaI4Q0
**TestMethod.java Kq&b1x
*/ +NWhvs
package NetFox; '0|0rwx
xo3bY6<n
Qau\6p>^
public class TestMethod { 3pg_`
Hj\>&vMf
KnK8\p88\
public TestMethod() kEiWE|
{ ///xx/weblogic60b2_win.exe uflRW+-2
try{ Mtxn@m{i;"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }8tD|t[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zpc R
SiteFileFetch fileFetch = new SiteFileFetch(bean); whFaL}2C
fileFetch.start(); ZyAm:yO
} jyB^a;-
catch(Exception e){e.printStackTrace ();} 1 ? be
sg0HYb%_E
OwRH :l
} 7HfA{.|m
L *",4!
bit@Kv1<C
public static void main(String[] args) Tk1U
{ 'PiQ|Nnb|
new TestMethod(); [HO=ii]Wb
} .YOC|\
} fP 4
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