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)); o5>/}wIf
} Pfm*<,'x"[
for(int i=0;i<nEndPos.length-1;i++) r9?o$=T
{ +hpSxdAz4
nEndPos = nStartPos[i+1]; @Eo4U]-
} {h,_"g\V
nEndPos[nEndPos.length-1] = nFileLength; oK)[p!D?0{
} @2u#93Y
} D{>\-]\
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E$w#+.QP
//启动子线程 z=B< `}@3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3i6h"Wu`n
for(int i=0;i<nStartPos.length;i++) \OP9_J(*
{ _y>}#6B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'v\j.j/i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W;.{]x.0
nStartPos,nEndPos,i); #L\o;p(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +miR3~w.
fileSplitterFetch.start(); ANotUty;y
} u-kZW1wrQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~*,Wj?~+7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <E SvvTf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U3/8A:$y
nEndPos = " + nFileLength); 0F1u W>D1
// fileSplitterFetch[nPos.length-1].start(); # J]~
;t|,nz4kJ
%w$mSG
//等待子线程结束 ?;_H{/)m
//int count = 0; E.9^&E}PG
//是否结束while循环 cg{Gc]'1#
boolean breakWhile = false; @/LiR>,
I :@|^PYw
[NL -!
while(!bStop) $5x]%1R
{ g#}tm<
write_nPos(); 9Yn)t#G'`F
Utility.sleep(500); y=#j`MH{>
breakWhile = true; o~;M"
@*SA$9/l
2Q}7fht
for(int i=0;i<nStartPos.length;i++) z#RuwB+
{ T!(sZf
if(!fileSplitterFetch.bDownOver) '=p?
{ BR3wX4i\
breakWhile = false; ?]5Ix1
break; (V!0'9c
} PGkCOmq
} C;ptir1G;
if(breakWhile) S_$nCyaH2
break; <W2ZoqaV
D&-vq,c
:kt/$S^-
//count++; F*,5\s<
//if(count>4) jC4O`
// siteStop(); xvB8YW"
} lA]N04 d
qEZ!2R^`G
]q&tQJ/Fa
System.err.println("文件下载结束！"); Bh,Q8%\6
} 8RU.}PD
catch(Exception e){e.printStackTrace ();} M|H2kvl
} AX K95eS
3 1k
"O``7HA}
//获得文件长度 %0zS
public long getFileSize() F)7j@h^
{ dWUUxKC
int nFileLength = -1; %jTw
try{ vzG ABP
URL url = new URL(siteInfoBean.getSSiteURL()); .lr5!Stb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mqw 84u
httpConnection.setRequestProperty("User-Agent","NetFox"); fdLBhe#9M
GL`tOD:P"
%4/xH9
int responseCode=httpConnection.getResponseCode(); 7 OWsHlU
if(responseCode>=400) MnS+nH!d
{ kIX)oD}c
processErrorCode(responseCode); dXK-&Po'
return -2; //-2 represent access is error &oEyixe
} {mf.!Xev
%/!+(7 D
G AEZY
String sHeader; ^vM_kArA
`O n(v
g>T
for(int i=1;;i++) H?{MRe
{ sG1BNb_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6n,xH!7
//Utility.log(in.readLine()); . pP7"E4]
sHeader=httpConnection.getHeaderFieldKey(i); d"GDZ[6
if(sHeader!=null) #Cx%OIi[f
{ }*Zo6{B-
if(sHeader.equals("Content-Length")) #R<G,"N5
{ 2vvh|?M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x`L+7,&n
break; KSsWjF}d
} s~Gw
} #g{Mne
else p[Hr39o
break; /=/ HB
} %"+4 D,'l
} }AJ L,Q7q
catch(IOException e){e.printStackTrace ();} L#!$hq9{_
catch(Exception e){e.printStackTrace ();} Gk 6fO
ib; yu_
BV1u,<T"
Utility.log(nFileLength); j.B>v\b_3
;j!UY.i
*v&*% B
return nFileLength; C=yD3mVz
} P9s_2KOF
8$m1eQ`{
T5q-"W6\
//保存下载信息（文件指针位置） `yYvYc
private void write_nPos() C]Q>*=r
{ ZMJ3NN]F
try{ 1OP"5f
output = new DataOutputStream(new FileOutputStream(tmpFile)); cd+^=esSO
output.writeInt(nStartPos.length); U3+A MVnB
for(int i=0;i<nStartPos.length;i++) m/{Y]D{2
{ &rP~`4Mkp
// output.writeLong(nPos); gwJ}]Tf
output.writeLong(fileSplitterFetch.nStartPos); #@E(<Pu4`
output.writeLong(fileSplitterFetch.nEndPos); zWtj|%ts
} =1IEpxh%
output.close(); vbedk+dd?A
} kU1 %f o
catch(IOException e){e.printStackTrace ();} F^]aC98]1
catch(Exception e){e.printStackTrace ();} ?Nu#]u-
} yi|:}K$
s.KOBNCFa
0R*}QXph
//读取保存的下载信息（文件指针位置） NN11}E6
private void read_nPos() GZS{&w!
{ RyE_|]I62u
try{ ,8~dz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zikm?(J
int nCount = input.readInt(); ]| z")gOE
nStartPos = new long[nCount]; 61kO1,Uz*
nEndPos = new long[nCount]; y}Cj#I+a
for(int i=0;i<nStartPos.length;i++) 0f{IE@-b
{ C[g&F0 6
nStartPos = input.readLong(); soDfi-2o3
nEndPos = input.readLong(); Yx!n*+:J
} s<,"Hsh^CR
input.close(); <ip)r;
} %uW<
catch(IOException e){e.printStackTrace ();} ZRO.bMgZF
catch(Exception e){e.printStackTrace ();} v|>BDN@,6
} }FZp840
g&P9UW>qS
-: C[P
private void processErrorCode(int nErrorCode) [RW,{A
{ F=VoFmF@
System.err.println("Error Code : " + nErrorCode); a0 qj[+
} /CbkqNV
r&=r/k2
WFXx70n
//停止文件下载 Xz" JY
public void siteStop() 9'l.TcVm`,
{ kr6:{\DU:B
bStop = true; |NXFla
for(int i=0;i<nStartPos.length;i++) ypxC1E
fileSplitterFetch.splitterStop(); S;BP`g<l=
IG>>j}
^T=5zqRD
} bnIf}ut-G
} ,znL,%s
//负责部分文件的抓取 gl Li
**FileSplitterFetch.java > d^r">!,
*/ } cRi A
package NetFox; u"eZa!#
$*g{[&L|6
^g\h]RD}
import java.io.*; -)<JBs>
import java.net.*; WGluZhRuT3
N:5b1TdI,
WI%zr2T
public class FileSplitterFetch extends Thread { eUYG96Jw
4U:DJ_GN
WtMcI>4w
String sURL; //File URL cS+?s=d
long nStartPos; //File Snippet Start Position v#w4{.8)
long nEndPos; //File Snippet End Position PVS\,
int nThreadID; //Thread's ID g\E ._ab<
boolean bDownOver = false; //Downing is over v!iWzN
boolean bStop = false; //Stop identical ^j1Gmv)
FileAccessI fileAccessI = null; //File Access interface )_WH#-}
sY&rbJ(P
*pmoLiuB>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9.^-us1
{ U. NeK{
this.sURL = sURL; MI?]8+l
this.nStartPos = nStart; qEPf-O:lm
this.nEndPos = nEnd; A5`#Ot*3
nThreadID = id; l[:^TfB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jD$;q7fB
} |P^ikx6f5
zaQ$ Ht
3~#ZE;>#
public void run() 6="M0%
{ 5B_-nYJDt
while(nStartPos < nEndPos && !bStop) -(`K7T>D.
{ :+kg4v&r
6f<*1YR F
AN50P!FZW
try{ \nn56o@eN
URL url = new URL(sURL); iLc)"L-i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YN$ndqOP
httpConnection.setRequestProperty("User-Agent","NetFox"); Ov F8&*A
String sProperty = "bytes="+nStartPos+"-"; 8uD8or
httpConnection.setRequestProperty("RANGE",sProperty); RRK^~JQI.2
Utility.log(sProperty); Mp}!+K
Nu>sp,|A
+F#=`+V
InputStream input = httpConnection.getInputStream(); )cfp(16
//logResponseHead(httpConnection); |E>v~qD8I
e-YGuWGN7
|s)VjS4@
byte[] b = new byte[1024]; R;5QD`
int nRead; wR`w@5,d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZP]2/;h
{ 77Q4gw~2U
nStartPos += fileAccessI.write(b,0,nRead); .N'%hh
//if(nThreadID == 1) 5M/%%Ox
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gwZ+GA
} ~GsH8yA_P
ZdJVs/33Vn
yHV^a0e7EH
Utility.log("Thread " + nThreadID + " is over!"); E` :ZH
bDownOver = true; !8H!Fj`|j
//nPos = fileAccessI.write (b,0,nRead); !xJLeQFJI]
} !;BZ#tF&
catch(Exception e){e.printStackTrace ();} w yuJSB
} Iqe=#hUFe!
} 0jl:Yzo&\
RBMMXJj
A,-[/Z K/
//打印回应的头信息 >n@>h$]
public void logResponseHead(HttpURLConnection con) 3M`hn4)K
{ uaZ"x&oZ#
for(int i=1;;i++) ru(?a~lF8~
{ q329z>
String header=con.getHeaderFieldKey(i); js%4;
if(header!=null) }kgjLaQ^N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %BT)oH}
Utility.log(header+" : "+con.getHeaderField(header)); QBN=l\m+
else s~IA},F,\
break; K{`2jK#
} VdjU2d
} Cz$Hk;3\6
jSOa
?[*@T2Ck
public void splitterStop() m,kvEQ3
{ |yId6v
bStop = true; * 7zN
} NUxAv= xl
.wt>.mUH
XQ+-+CD
} @hz0:ezg:
_mI:Lr#dT
Y`[HjS,
/* l72ie
**FileAccess.java hCOy\[2$
*//文件访问(定位，写) sbq44L)
package NetFox; +lXdRc`6
import java.io.*; qAuUe=w%p
O #p)~V8~
0N} wD-
public class FileAccessI implements Serializable{ ;{F;e)${M
o#KPrW`XJ/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >k&lGF<nl
RandomAccessFile oSavedFile; eW }jS/g`
long nPos; JXI+k.fi
~$TE
gw}7%U`T9
public FileAccessI() throws IOException 0 6G[^
{ 6{FS/+
this("",0); w$<fSe7
} v=yI#5
QBBJ1U
[K|>s(Sf*
public FileAccessI(String sName,long nPos) throws IOException Br.$L
{ (fLbg,
oSavedFile = new RandomAccessFile(sName,"rw"); =>9.@`.
this.nPos = nPos; <}x|@u
oSavedFile.seek(nPos); MIMPJXT#.
} )MX1776kU
?-6x]l=]
O}\"$n>
public synchronized int write(byte[] b,int nStart,int nLen) jW+VUF-t
{ hnfrnYH
int n = -1; QeOt;{_|
try{ S92!jp/
oSavedFile.write(b,nStart,nLen); MM58w3Mz
n = nLen; #VMBn}
} ~]t2?SqNm
catch(IOException e) yI)RGOV
{ (/rIodHJO
e.printStackTrace (); 3 v,ae7$U&
} F" #3s=
ju2X*
m} FCe
return n; O.40^u~
} IB]VPj5
+Muia5G
BOl$UJ|K
} b3HTCO-,fC
J|64b
_tauhwu
/* @0@'6J04
**SiteInfoBean.java "=5vgg3
*/ <xh'@592
package NetFox; =ym~= S
.qU%SmQ^
vEee/+1?
public class SiteInfoBean { A"T. nqB^y
#}]il0d
3E2.v5*
private String sSiteURL; //Site's URL fB ,!|u
private String sFilePath; //Saved File's Path Tk@g9\6O9
private String sFileName; //Saved File's Name {CyPcD'$s
private int nSplitter; //Count of Splited Downloading File sCf(h
kpMM%"=V
2W-NCE%K)T
public SiteInfoBean() A,CPR0g%
{//nSplitter的缺省值为5 0{Ll4
//default value of nSplitter is 5 pUEok+
this("","","",5); W&re;?Z{ke
} Q8/0Cb/
D@vvy6>~s
';L^mxh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O=?X%m #
{ y.]]V"'2
sSiteURL= sURL; ((IBaEq
sFilePath = sPath; 2n+XML
sFileName = sName; (/P&;?j
this.nSplitter = nSpiltter; ke6cZV5w
hy`)]>9z~
(9q{J(44
} N %/DN
V$F.`O!hfi
*gpD4c7A\
public String getSSiteURL() ,ce^"yG
{ q>oH(A
return sSiteURL; />I8nS}T
} 0*M}QXt
Y,Zv0-"
:H8L(BsI
public void setSSiteURL(String value) g[+Q~/yq
{ o 0 #]EMr
sSiteURL = value; U$JIF/MO_
} WsDe0F
>\x 39B
G(3la3\(
public String getSFilePath() E&tmWOMj>
{ DWxh{h">
return sFilePath; } K-[/;
} pPoC61F
[k{iN1n
Q>c6ouuJ
public void setSFilePath(String value) T[=cKYp8\
{ 7?WBzo!!L
sFilePath = value; w=>mG-
} +rO<'H:umJ
4'[ V'c\
H 1X]tw.
public String getSFileName() 54DR.>O
{ X',0MBQ0
return sFileName; q _|5,_a
} ?v~3zHK
0!\q
7Cp_41._
public void setSFileName(String value) FAl6
{ u9~J1s<e
sFileName = value; ;<R_j%*
} ~"0X,APR5
_%%"Y}
(>`SS#(T!
public int getNSplitter() Ui;s.f
{ 5&Kn #
return nSplitter; ho$%7mc
} GQBN-Qv
F@K;A%us)
;@s~t:u
public void setNSplitter(int nCount) fR;_6?p*B
{ ov>L-
nSplitter = nCount; BtApl)q#
} eE_XwLE
} 7f,WzvV
C2i..iD
Hxi=\2-
/* ,w>?N\w!}
**Utility.java Dx)XC?'xO
*/ *lF%8k"Al
package NetFox; U {!{5l:
xmx;tq
g$LwXfg
public class Utility { fG5}'8
ID+k`nP
hkI);M+@6
public Utility() 0 d]G
{ Khd,|pM
i_ TdI
(.+n1)L?
} l);8y5
N)Kr4GC
//线程睡眠 ~riw7"
public static void sleep(int nSecond) R?SHXJ%'
{ rcT<OiYuig
try{ 1R9/AP
Thread.sleep(nSecond); !S{<Xc'wv
} EBLoRW=8ld
catch(Exception e) z59J=?|
{ _S1uJ~j;E
e.printStackTrace (); FR"^?z?}p
} j-|0&X1C
} Or>[_3
<2d@\"AoHE
//日志 1X.1t^HH:
public static void log(String sMsg) S}O\<6&
{ tn1aH +
System.err.println(sMsg); $g;xw?~#
} yG4MqR)J
Z.JTq~`I
[L^#<@S
public static void log(int sMsg) s&</zU'
{ UkV] F]
System.err.println(sMsg); k3XtKPO
} ;Vt u8f
} (J*0/7 eX
&pz8vWCk
~]W8NaQB(
/* p6)UR~9Rs
**TestMethod.java iN*@f8gf
*/ %-CC_R|0$
package NetFox; V ""
lR!$+atW
= xk@Q7$
public class TestMethod { y"ck;OQD
LAeXe!y
u'p J9>sC
public TestMethod() r N7"%dx
{ ///xx/weblogic60b2_win.exe 6wgOmyJx
try{ !Ao?bs'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2Mda'T8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9iE66N>z
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]'q<wPi
fileFetch.start(); t/g}cR^Q
} e)kf;Hkf
catch(Exception e){e.printStackTrace ();} n6f|,D!?
9':$!Eoq
T_WQzEL^
} e j9G[
<4g^c&
4SYN$?.Mp
public static void main(String[] args) %`'VXR?`h=
{ W#!\.m`5
new TestMethod(); ?x@khzk
} XvdhPOMy
} +,lD_{}_
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