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)); Hd)4_ uBt
} dLm~]V3
for(int i=0;i<nEndPos.length-1;i++) U.G**v
{ ;[@< ,
nEndPos = nStartPos[i+1]; Ui7S8c#tH
} u1&pJLK0[
nEndPos[nEndPos.length-1] = nFileLength; Ij}RlYQz
} LdAfY0
} "tbKKh66
b#^UP
;,]T|>M
//启动子线程 jxr~cp?4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fNx3\<~V=
for(int i=0;i<nStartPos.length;i++) X] &Q^
{ m>'sM1s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fgP_NYfOj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tq^H)
nStartPos,nEndPos,i); T?c:z?j_9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >_]j{}~\k
fileSplitterFetch.start(); }CA oB::&
} Uok?FEN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lM5Xw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =?3D:k7z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t3b%f`D
nEndPos = " + nFileLength); N$H0o+9-Y
// fileSplitterFetch[nPos.length-1].start(); AjK'P<:/
g#1_`gK
Jn.WbS
//等待子线程结束 g~Zel}h#
//int count = 0; ,\f!e#d
//是否结束while循环 `Q*L!/K+
boolean breakWhile = false; 0t1WvW
{ CkxUec
<w.W[ak
while(!bStop) V3-5:z
{ b$+.}&M
write_nPos(); 0Q=4{*:?
Utility.sleep(500); A5zT^!`[
breakWhile = true; 'tp1|n/1
vO"Sy{)Z>
Os@ d&wm
for(int i=0;i<nStartPos.length;i++) Bls\)$
{ %9xz[Ng
if(!fileSplitterFetch.bDownOver) 41WnKz9c
{ B`}?rp
breakWhile = false; .S17O}
break; n97A'"'wz
} wz5xJ:Tj
} keEyE;O}u
if(breakWhile) 70l"[Y
break; &CFHH"OsT
/v E>*x
w9h\J#f
//count++; i!<,8e=
//if(count>4) auqM>yx
// siteStop(); ao<@a{G
} BM#cosV7%h
"8aw=3A
iNgHx[*?
System.err.println("文件下载结束！"); XS]=sfN
} M& GA:`
catch(Exception e){e.printStackTrace ();} cTFyF)
} rE-Xv. |
CEE`nn
;Id%{1
//获得文件长度 6)kF!/J
public long getFileSize() b/ h,qv
{ oBQr6-nZ
int nFileLength = -1; P7(+{d{
try{ JGp~A#H&
URL url = new URL(siteInfoBean.getSSiteURL()); &+=A;Y)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EUU9JnQhBJ
httpConnection.setRequestProperty("User-Agent","NetFox"); C+$dm)M/q
iK1<4)
1K&z64Q5J
int responseCode=httpConnection.getResponseCode(); [J0L7p*6
if(responseCode>=400) Y!v `0z
{ G:$wdT(u
processErrorCode(responseCode); Iu^#+n
return -2; //-2 represent access is error k`6T% [D]
} Zg%U4m:
l~wx8 ,?G
P}y}IR{6
String sHeader; ^_r8R__S:
eXWiTi@
_) 2fXG!
for(int i=1;;i++) l=[<gPE
{ =9GL;z:R+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .0S.7w3dZo
//Utility.log(in.readLine()); b40zYH`'{
sHeader=httpConnection.getHeaderFieldKey(i); 5@bLDP
if(sHeader!=null) KD*,u{v;
{ !9DqW&8
if(sHeader.equals("Content-Length")) ' D+h_*H
{ d>eVR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CeoK@y=o
break; "d>{hP
} r}MXXn,f
} ` ZXX[&C
else gX5I`mm
break; dU\,>3tG
} V6?ku6k
} $%"i|KTsv:
catch(IOException e){e.printStackTrace ();} 1 e1$x@\\
catch(Exception e){e.printStackTrace ();} IL?3>$,
v{^_3 ]
wP- pFc
Utility.log(nFileLength); f@T/^|`mh
ZFNM>C^
2j`x^
return nFileLength; ]fIv{[A_
} MbC7`Sp&i
#.UooFk+Y
(EGsw o
//保存下载信息（文件指针位置） v-J*PB.0p
private void write_nPos() ;(fDR8
{ Q5b?- P
try{ h.ojj$f,
output = new DataOutputStream(new FileOutputStream(tmpFile)); *fso6j#%
output.writeInt(nStartPos.length); RxY ;'NY
for(int i=0;i<nStartPos.length;i++) -mOSB(#bo
{ A9ia[2[
// output.writeLong(nPos); wGD".CS0
output.writeLong(fileSplitterFetch.nStartPos); x'@0]f.
output.writeLong(fileSplitterFetch.nEndPos); tbF>"?FY/
} Nt9M$?\P
output.close(); A1zM$ wDU
} *x2+sgSf_0
catch(IOException e){e.printStackTrace ();} |Xk'd@<
catch(Exception e){e.printStackTrace ();} _>%P};G{>
} 2i*-ET
mBSa*s)
W#E`h
//读取保存的下载信息（文件指针位置） *P_(hG&c
private void read_nPos() 4=td}%
{ CTQF+Oe8O
try{ [URo#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hC?:XVt
int nCount = input.readInt(); $As;Tvw.
nStartPos = new long[nCount]; @|v4B[/
nEndPos = new long[nCount]; <61T)7
for(int i=0;i<nStartPos.length;i++) Vrzx;V%
{ eTemRNz
nStartPos = input.readLong(); n~l9`4wJY
nEndPos = input.readLong(); q%%8oaEI
} NypM+y
input.close(); @&t';"AE
} hJ\IE?+
catch(IOException e){e.printStackTrace ();} 1r;]==
catch(Exception e){e.printStackTrace ();} qZACX.Hw
} =<R")D]4z
R)MWO5
%^f!= *
private void processErrorCode(int nErrorCode) xDv$z.=Y
{ i"Hec9Ri
System.err.println("Error Code : " + nErrorCode); Md(AqaA
} AM cHR=/
>UvLeS2h:y
t+7h(?8L
//停止文件下载 @^]wT_r
public void siteStop() 9J h"1i>x2
{ jh0``{
bStop = true; l{ja2brX
for(int i=0;i<nStartPos.length;i++) JpqZVu"7
fileSplitterFetch.splitterStop(); _jg&}HM
u:AKp<'
xDU>y
} lx$]f)%~
} ivDmPHj{
//负责部分文件的抓取 8+Sa$R
**FileSplitterFetch.java {q fgvu
*/ f#mBMdj
package NetFox; /8(c^
~XGBE
I[,tf!
import java.io.*; dCv@l7hE
import java.net.*; &HBqweI
i3#To}g5V
idW=
public class FileSplitterFetch extends Thread { b5K6F:D22
I,;@\
P"d7Af
String sURL; //File URL Y|JC+Ee
long nStartPos; //File Snippet Start Position $BHbnsaQ
long nEndPos; //File Snippet End Position 5p!X}u]
int nThreadID; //Thread's ID ^'>kZ^w0
boolean bDownOver = false; //Downing is over 4g<F."
boolean bStop = false; //Stop identical h!.#r*vV
FileAccessI fileAccessI = null; //File Access interface u"eO&Vc
zj:= 9$
!lQGoXQ'4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D+edTAQ8
{ YuufgPE*H
this.sURL = sURL; i4;`dCT|A
this.nStartPos = nStart; ${I$@qq83
this.nEndPos = nEnd; x?s5vxAKf
nThreadID = id; xuBXOr4"P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5@l[!Jl0k
} XRoMD6qf;
GZJIIP#
l{q$[/J~)
public void run() Z9Prw/8P
{ K5l#dl_T
while(nStartPos < nEndPos && !bStop) [O~'\Q
{ s}"5uDfn1F
:lf;CT6$
OSP#FjH
try{ ~DY5`jV
URL url = new URL(sURL); d'j8P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @;>i3?
httpConnection.setRequestProperty("User-Agent","NetFox"); OS|uZ<"Rq3
String sProperty = "bytes="+nStartPos+"-"; &XG k
httpConnection.setRequestProperty("RANGE",sProperty); kkWqP20q
Utility.log(sProperty); w&&uk[Gh/a
*;^!FBT
QY14N{]T\p
InputStream input = httpConnection.getInputStream(); }{FKs!(4
//logResponseHead(httpConnection); P$l-p'U-
Ce&nMgd~
o=/Cje
byte[] b = new byte[1024]; R}~p1=D
int nRead; 9J>b6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (EZ34,k'S
{ ?naPti1GX
nStartPos += fileAccessI.write(b,0,nRead); p#-ov-znp
//if(nThreadID == 1) lIR0jgP@z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hgu:*iYA
} H<tk/\C
<eWGvIEP[
$xx5+A%,
Utility.log("Thread " + nThreadID + " is over!"); /rMxl(wD'
bDownOver = true; |GmV1hN
//nPos = fileAccessI.write (b,0,nRead); #bRr|`
} ;VQFz&Q$u
catch(Exception e){e.printStackTrace ();} 9{OH%bF
} Eu%19s;u
} oL?[9aww
t:A,pT3
00DWXGt20o
//打印回应的头信息 $#Mew:J
public void logResponseHead(HttpURLConnection con) 1-z*'Ghys
{ xL.T}f~y2>
for(int i=1;;i++) {sn:Lj0
{ 'Na \9b(
String header=con.getHeaderFieldKey(i); -I, _{3.S
if(header!=null) 44s K2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]J=S\
Utility.log(header+" : "+con.getHeaderField(header)); >;E[XG^
else !83x,*O
break; q;I`&JK
} B@ab[dm280
} iEDZ\\,
{?a9>g-BW
R'E8>ee;^
public void splitterStop() Y~RZf /`
{ 7V/yU5
bStop = true; 7e,<$PH
} +{%@kX<V_
+n1jP<[<N
^iaeY jI
} vBUl6EmWu
OtopA)
?nm:e.S+?
/* !U02>X
**FileAccess.java >M` swEj
*//文件访问(定位，写) Kd_WN;l
package NetFox; )G(6=l*
import java.io.*; ^V^In-[!y:
#=WDJT:
K#"@nVWJ.m
public class FileAccessI implements Serializable{ <`dF~
qZ!1>`B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \!UNale
RandomAccessFile oSavedFile; S"|sD|xOb
long nPos; M/U$x /3K
_ Ko0
0F'75
public FileAccessI() throws IOException CK e
{ ]{9oB-;,
this("",0); ?KxI|os
} .js4)$W^
-;$+`<%
W7NHr5RC
public FileAccessI(String sName,long nPos) throws IOException 7YRDQjg
{ =q|fe%#
oSavedFile = new RandomAccessFile(sName,"rw"); uTJi }4cw
this.nPos = nPos; D#%J||
oSavedFile.seek(nPos); ?o0#h
} dRZor gar
XEqg%f
S(A0),
public synchronized int write(byte[] b,int nStart,int nLen) d9/E^)TT
{ w'=#7$N
int n = -1; *D1fSu!
try{ z(< E %
oSavedFile.write(b,nStart,nLen); X7kJWX
n = nLen; ;>=hQC{f>
} Q:+Y-&||"
catch(IOException e) K*J8(/WkD
{ a@@!Eg A
e.printStackTrace (); vg5zsR0u
} 8Gb=aF1
hoC}@8_
.Jdw:
return n; ?Di,'
} ?xf59mY7
yZ&By?.0
yZ:|wxVY
} cFLu+4.jsG
F *; +-e
+ZXGT
/* Rn{q/h
**SiteInfoBean.java 2h&pm
*/ ;J\{r$q
package NetFox; BN4dr9T
)<.S3
pb%#`2"
public class SiteInfoBean { 3Gn2@`GC
9BANCW"
HkvCQH
private String sSiteURL; //Site's URL c7\bA7.
private String sFilePath; //Saved File's Path !U`T;\,v5
private String sFileName; //Saved File's Name p)ZlQ.d#Y
private int nSplitter; //Count of Splited Downloading File ?l,i(I
+bm2vIh$
f.jAJ; N>
public SiteInfoBean() 6o;lTOes
{//nSplitter的缺省值为5 ]CC= \<
//default value of nSplitter is 5 ;_j\E(^%
this("","","",5); .WL507*"Ce
} w& RpQcV
mQ%kGqs
9+QLcb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NtTLvO6
{ =mqV&FgRo
sSiteURL= sURL; lO, 2
sFilePath = sPath; j<deTK;.
sFileName = sName; b&~uK"O'7d
this.nSplitter = nSpiltter; #Mbt%m
!^axO
#bu`W!p}
} mKpUEJ<a
k5-mK{RZ
-I=}SZ
public String getSSiteURL() qUtVqS
{ XQ(`8Jl&^
return sSiteURL; rvE!Q=y~
} >^J!Z~;L)
lYw A5|+
'%RMpyK~
public void setSSiteURL(String value) 1rPeh{SZ
{ c<&+[{|
sSiteURL = value; 4kXx(FE
} .h+<m7
YSrFHVq
ObM5vrEk|
public String getSFilePath() }Pb!u9_
{ WgPL4D9=
return sFilePath; 5RLK]=
} 5 (H; x74
==FzkRA)
VDnAQ[T@d
public void setSFilePath(String value) E#ys-t 42
{ Z<,gSut'Y
sFilePath = value; Kv#daAU
} aRG[F*BY
P`bR;2o
?tA-`\E
public String getSFileName() G~esSL^G/
{ J"83S*2(j
return sFileName; 0_]aF8j
} 0)2lBfHQ&
wG{obsL.!
VGvOwd)E
public void setSFileName(String value) G,"$Erx
{ 4|+ |L_
sFileName = value; qw, >~
} _^'k_a
;%k%AXw
t#pY2!/T3
public int getNSplitter() Gc 8
{ .`h+fqa
return nSplitter; O3BU.X1'%
} to?"{
hXrvb[6
pP/o2
public void setNSplitter(int nCount) #ASu SQ
{ lmc-ofEv
nSplitter = nCount; 8v6rS-iHP
} `UJW:qqW
} v'@LuF'e8
^#t<ILUa
SQ1&n;M}f
/* cEQa 6
**Utility.java [cW
*/ vCmh3TQ
package NetFox; mE7Jv)@
aEM#V
&GZR-/
public class Utility { O~Fk0}-
:YI>AaYWDO
9(PFd%
public Utility() k m|wB4
{ $7bmUQ|
CKR9APkv
P<(mH=K
} QA9vH'
z"vgwOP su
//线程睡眠 nm~
public static void sleep(int nSecond) J~Ph)|AiS
{ >WEg8'#O
try{ nagto^5X
Thread.sleep(nSecond); vVf!XZF
} )/pPY
catch(Exception e) Z"^@B2v
{ enrmjA&3
e.printStackTrace (); mT9\%5d3
} A&7jE:Ew
} puyL(ohem
j w462h
//日志 >k#aB.6
public static void log(String sMsg) {2Ibd i
{ ;5l|-&{@*
System.err.println(sMsg); [eN{Ft0x
} 6qDD_:F
NNdS:(
Yt'o#"R)
public static void log(int sMsg) ~S6N'$^
{ iTvCkb48m
System.err.println(sMsg); =w8 YZs8w
} Lgfr"{C
} srkOad
ou-;k }
/W>"G1)
/* 7L6M#B[)e5
**TestMethod.java <>oW f
*/ iau&k`b`
package NetFox; ]]ZBG<#
5~F0'tb|}
!R@4tSu
public class TestMethod { f*~fslY,o
pp`U]Q5"gX
G<eJ0S
public TestMethod() a+i+#*8wm
{ ///xx/weblogic60b2_win.exe gD\}CxtG
try{ DIAP2LR ?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ATHz~a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 463dLEd
SiteFileFetch fileFetch = new SiteFileFetch(bean); }{y$$X<:
fileFetch.start(); BSf"'0I&
} u\wd<<I']
catch(Exception e){e.printStackTrace ();} qh 3f
xL"%2nf
F)w83[5_d
} dp70sA!JF
}+J@;:
g <o;\\
public static void main(String[] args) VLN3x.BY
{ n}?G!ySg
new TestMethod(); 7A6sSfPUy
} }b(e
} J5T#}!f
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