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)); O|'1B>X
} Ll}yJ#3,
for(int i=0;i<nEndPos.length-1;i++) K 1W].(-@4
{ !20XsO
nEndPos = nStartPos[i+1]; Bp_wnd
} ?obm7<
nEndPos[nEndPos.length-1] = nFileLength; G5Ykbw#
} bRsTBp;R`I
} tj5giQ3DG)
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tC)6
//启动子线程 L0"~[zB]N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~x]9SXD%
for(int i=0;i<nStartPos.length;i++) Dl,`\b@Fw3
{ 2*1ft>Uty
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7x k|+!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /+[63=fl
nStartPos,nEndPos,i); 1@qgF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ."6[:MF
fileSplitterFetch.start(); lr3mE
} d%ME@6K)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hj6'pJ4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ue{xnjw>U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,={t8lN
nEndPos = " + nFileLength); X.V[0$.;
// fileSplitterFetch[nPos.length-1].start(); L:R<e#kgS
\#Up|u:
DL8x":;
//等待子线程结束 @S3f:s0~D
//int count = 0; Yj3I5RG
//是否结束while循环 XKU=oI0\j
boolean breakWhile = false; <<zI\+V
!mnUdR|>(
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while(!bStop) {C3Y7<
{ 3yO=S0`
write_nPos(); 'i|rjW(
Utility.sleep(500); eV};9VJ$F
breakWhile = true; .*5Z"Q['G
~Xv=9@,h
`dW]4>`O
for(int i=0;i<nStartPos.length;i++) w0J|u'H
{ \".^K5Pm
if(!fileSplitterFetch.bDownOver) D4u%6R|F
{ Q[u6|jRt
breakWhile = false; wkb$^mU
break; A9:NKY{z
} uGVy6,
} Da1aI]{I
if(breakWhile) I'!/[\_
break; *?% k#S
egR-w[{
QlZ@ To
//count++; ^ c%N/V \
//if(count>4) T.:+3:8|F
// siteStop(); B80aw>M
} e%O0hE
k$i'v:c|:i
=o7}]k7
System.err.println("文件下载结束！"); md Gwh7/3
} zsQoU&D 5
catch(Exception e){e.printStackTrace ();} l*=aMjd?
} EqB)sK/3
N{Qxq>6 G
,xsH|xW
//获得文件长度 nE W31 8
public long getFileSize() sRhKlUJG
{ *_-'/i
int nFileLength = -1; j`>^1Q
try{ !CY&{LEYn0
URL url = new URL(siteInfoBean.getSSiteURL()); [iS$JG-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iCQ>@P]nE
httpConnection.setRequestProperty("User-Agent","NetFox"); 7jG(<!,
XNH4vG |
19U]2D/z
int responseCode=httpConnection.getResponseCode(); !{%:qQiA
if(responseCode>=400) _^ |2}t
{ dJk9@u
processErrorCode(responseCode); ,!QV>=
return -2; //-2 represent access is error ;0%OB*lcgE
} iThSt72
83Ou9E!W
zGo|JF
String sHeader; K\?]$dK5
K7)kS
k;^ :
for(int i=1;;i++) uE5X~
{ e":G*2a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vGd1w%J-
//Utility.log(in.readLine()); &, a3@i
sHeader=httpConnection.getHeaderFieldKey(i); Fke//- R
if(sHeader!=null) o>]`ac0b}Y
{ C(?blv-vM0
if(sHeader.equals("Content-Length")) bn9;7`>.
{ zw@'vncc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o^p
break; M[]A2'fS
} L:&k(YOBA
} E8[T
else v3[@1FQ"
break; TLa]O1=Bf.
} o*S"KX$
} X[$++p .
catch(IOException e){e.printStackTrace ();} t#E}NR
catch(Exception e){e.printStackTrace ();} eVh-_
Sus;(3EX
QO;4}rq
Utility.log(nFileLength); % ZU/x d
0#p/A^\#7M
e]8,:Gd(
return nFileLength; Am4lEvb
} 6sfwlT
oYM3Rgxf9Q
hVpCB,
//保存下载信息（文件指针位置） TD@v9
private void write_nPos() :$3oFN*g
{ WgQBGch,!
try{ rSXzBi{
output = new DataOutputStream(new FileOutputStream(tmpFile)); (8a#\Y[b
output.writeInt(nStartPos.length); pbXi9|bI
for(int i=0;i<nStartPos.length;i++) aptY6lGv-|
{ tOl e>]
// output.writeLong(nPos); K95;rd
output.writeLong(fileSplitterFetch.nStartPos); %3Z/+uT@v]
output.writeLong(fileSplitterFetch.nEndPos); kSncZ0K{
} j Ch=@<9
output.close(); Q4]4@96Aj
} kLSrj\6I[
catch(IOException e){e.printStackTrace ();} ?)4?V\$
catch(Exception e){e.printStackTrace ();} y(jg#7)
} E+95WF|4k"
cQNsL
]2SI!Ai7
//读取保存的下载信息（文件指针位置） /B3R1kNf|
private void read_nPos() ^C)n$L>C0
{ '-$XX%TOAc
try{ Rqipkx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tfO#vw,@
int nCount = input.readInt(); q>!L6h5]t
nStartPos = new long[nCount]; i^`9syD
nEndPos = new long[nCount]; 256LHY|6
for(int i=0;i<nStartPos.length;i++) ~l[ra
{ 3INI?y}t
nStartPos = input.readLong(); mB'3N;~
nEndPos = input.readLong(); jdA ]2]
} v-j3bB
input.close(); OW;tT=ql
} $^/0<i$
catch(IOException e){e.printStackTrace ();} <i\A_qqc/
catch(Exception e){e.printStackTrace ();} C@\{ehG
} knp>m,w
S^I,Iz+`S'
>H][.@LyR
private void processErrorCode(int nErrorCode) QbFHfA2Ij
{ q<vf,D@{ !
System.err.println("Error Code : " + nErrorCode); I&yVx8aH}
} Wzq>JNny
c~}l8M%
Tb;d.^
//停止文件下载 M)-6T{[IT
public void siteStop() \ gwXH
{ J97R0
bStop = true; koG{ |elgB
for(int i=0;i<nStartPos.length;i++) ]$-cMX
fileSplitterFetch.splitterStop(); 8TV;Rtl
b,H[I!. %
TA18 gq
} LwqC~N
} -;(Q1)&
//负责部分文件的抓取 =HDI \LD<
**FileSplitterFetch.java q Dd~2"er
*/ }Nj97R
package NetFox; j1$8#/r;c
RF}X ER
j-@kW'K
import java.io.*; @r^!{
import java.net.*; q}|U4MJm
M+>`sj
%V G/
public class FileSplitterFetch extends Thread { b]Kk2S/
6(&Y(/
.\Fss(Zn
String sURL; //File URL U%B(5cC
long nStartPos; //File Snippet Start Position b}!3;:iD
long nEndPos; //File Snippet End Position AbwbAm+
int nThreadID; //Thread's ID }alj[)
boolean bDownOver = false; //Downing is over <~emx'F|
boolean bStop = false; //Stop identical }3 m0AQ;K
FileAccessI fileAccessI = null; //File Access interface [onqNp
BbOu/i|
or*HC&c7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =v~1qWX
{ AnsjmR:Jv
this.sURL = sURL; _;9!
this.nStartPos = nStart; Xt/Ksw"wn
this.nEndPos = nEnd; 8kL4~(hY
nThreadID = id; R,2=&+e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D>L2o88
} K<sCF[
WKM)*@#,
"@3@/I
public void run() 8ovM\9qT
{ 4R%*Z~
while(nStartPos < nEndPos && !bStop) .\3`2
{ 'm=*u SJK
H!IshZfktn
7k%T<;V
try{ 5ABhj*7
URL url = new URL(sURL); fIC9WbiH-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P'Q$d+F,
httpConnection.setRequestProperty("User-Agent","NetFox"); SkNre$>t{
String sProperty = "bytes="+nStartPos+"-"; j=+"Qz/hr_
httpConnection.setRequestProperty("RANGE",sProperty); ^H'a4G3
Utility.log(sProperty); 4NR@u\S
/?-7Fg+,
i8X`HbmN
InputStream input = httpConnection.getInputStream(); ;Q0bT`/X
//logResponseHead(httpConnection); =1;=
9W`Frx'h1
NmIHYN3
byte[] b = new byte[1024]; B6P|Z%E;D6
int nRead; V}w;Y?]J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aT l c
{ x<i}_@Sn_+
nStartPos += fileAccessI.write(b,0,nRead); R>@uY(>dJ
//if(nThreadID == 1) t=euE{c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!e(A ]&
} `\|ssC8u
NF$\^WvYSP
d5I f"8`@
Utility.log("Thread " + nThreadID + " is over!"); &xZyM@
bDownOver = true; '(&%O8Yi
//nPos = fileAccessI.write (b,0,nRead); JWP*>\P
} V:NI4dv/R
catch(Exception e){e.printStackTrace ();} =ziwxIo6
} -ZOBAG*
} C&\5'[*
cp Ear
,38Eq`5&W
//打印回应的头信息 Ok-.}q>\Mv
public void logResponseHead(HttpURLConnection con) *~$~yM/~3U
{ #1-xw~_
for(int i=1;;i++) ~q +[<xR\
{ =TvzS%U
String header=con.getHeaderFieldKey(i); 0"k|H&
if(header!=null) @MR?6n*k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mq%,lJA\
Utility.log(header+" : "+con.getHeaderField(header)); <msxHw
else RH;:9_*F
break; _#$9 y1bd
} bucR">_p
} 7Ob*Yv=[
_+f+`]iM
D]! aT+
public void splitterStop() %Tn#-
{ N^?9ZO
bStop = true; v]:=K-1n
} *y[PNqyd
1m<RwI3s
R614#yn-+
} |w}w.%
:HViX:]H
#:fQ.WWO
/* 1MkI0OZE
**FileAccess.java ^W83ByP
*//文件访问(定位，写) G1T^a>tj4
package NetFox; Q'apG)0I
import java.io.*; )w~Fo,
8U2dcx:G3
(3vHY`9
public class FileAccessI implements Serializable{ T>>YNaUL
92W&x'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aiCFH_H4;L
RandomAccessFile oSavedFile; -l+P8:fL~
long nPos; w&&2H8
JYqSL)Ta*t
[jx0-3s:X
public FileAccessI() throws IOException lEL78l.
{ Tq<2`*Qs
this("",0); ihL/n
} 05\dl
>gtQw!
$*[{J+t_
public FileAccessI(String sName,long nPos) throws IOException dBCbL.!
{ |BMV.Zi
oSavedFile = new RandomAccessFile(sName,"rw"); @# P0M--X
this.nPos = nPos; R_P}~l
oSavedFile.seek(nPos); &Jc_Fc(M
} -XoPia2
pI`?(5iK6|
~.Ik#At
public synchronized int write(byte[] b,int nStart,int nLen) <M?:
{ |Q~cX!;
int n = -1; S|AM9*k9
try{ "pxzntY|
oSavedFile.write(b,nStart,nLen); &YP#M|
n = nLen; USJ-e
} H2gj=krK
catch(IOException e) QA!_} N4n
{ s,VXc/
e.printStackTrace (); |8_JY2 R
} UQCo}vM
k?nQ?B W
w-B^ [<
return n; ^yviV Y
} 10Wz,vW,n
]T! }XXK
#1'\.v
} {X]R-1>
9Vuq,dv
pC,o2~%{
/* 3{%LS"c
**SiteInfoBean.java 59uwB('|lH
*/ gB,G.QM*6
package NetFox; S&nxok`e^
ewNz%_2
:!&;p
public class SiteInfoBean { qMBR *f
zZ-wG
;.sl*q1A
private String sSiteURL; //Site's URL t,)N('m}=
private String sFilePath; //Saved File's Path VvbFp
private String sFileName; //Saved File's Name MWk:sBCqr
private int nSplitter; //Count of Splited Downloading File ;#GoGb4AM
jd`},X/
tL SN`6[:
public SiteInfoBean() $Kj&)&M
{//nSplitter的缺省值为5 %b.UPS@I
//default value of nSplitter is 5 q}Z3?W
this("","","",5); T70QJ=,
} 23(=Xp3;>
73A)lU.
iJFs0?*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .ujT!{>v/
{ yj6@7@l>A
sSiteURL= sURL; rI$`9d
sFilePath = sPath; `pZs T ^G[
sFileName = sName; ^62|d
this.nSplitter = nSpiltter; Rr(* aC2P
j Ib
~\nBjM2
} ;32#t[ib
C) QKPT
EY`H}S!xy
public String getSSiteURL() g_*T?;!.U
{ 8?t"C_>*e
return sSiteURL; egR9AEJvz
} O[17";P
s}&bJ"!Z
RIM`omM
public void setSSiteURL(String value) "yziXT@V
{ Thy=yz;p
sSiteURL = value; $DFv30 f
} QlFZO4 P3|
+YOKA*
qJ!Z~-hS
public String getSFilePath() 39U5jj7i
{ +eQe%U
return sFilePath; Mkp/0|Q*
} k?BJdg)xJ
qVjWV$j
5lKJll^2:
public void setSFilePath(String value) %ugHhS!
{ MJ<Jb,D1
sFilePath = value; ~pk(L[G
} HWns.[
V=I"-k}RL
&WXY'A=
public String getSFileName() E9j+o y
{ T&Xl'=/
return sFileName; >>l`,+y
} uD_v!
4Ph0:^i_
vP%tk s+.
public void setSFileName(String value) ~jU/<~s
{ \u-0v.+|
sFileName = value; Mj>}zbpk/
} js^ ,(CS
~Vh(6q.oT
.Hhhi
public int getNSplitter() pN6%&@) =
{ C<^YVeG
return nSplitter; D\~zS`}
} -kz4FS
{>3\N0e5
|s7`F%
public void setNSplitter(int nCount) )'4P.>!!aQ
{ rsn.4P=
nSplitter = nCount; (w(
} {n3EGSP#
} uy_wp^
cxeghy:;U
3:/'t{ ^B
/* xVB;s.'!
**Utility.java {3a&1'a0g
*/ XKL3RMF9r
package NetFox; 3gWvmep1
aIy*pmpD=
U=Y)V%
public class Utility { 1[F3 Z
sRVIH A,
C-eA8pYY/
public Utility() -Ue$T{;RoH
{ \mM<\-'p
|rw%FM{F
0X8t>#uF
} !{et8F@d|
Xm2\0=v5;
//线程睡眠 j!~l,::$"X
public static void sleep(int nSecond) Kyt)2p
{ 'XQ`g CF=
try{ <oKGD50#
Thread.sleep(nSecond); l}^3fQXI
} Kemw^48ts
catch(Exception e) GY3Wj
{ ;rI@*An
e.printStackTrace (); zQ?!f#f
} 'mCe=Y
} 2=0DCF;Bv
A,-6|&F
//日志 ;a=w5,h:
public static void log(String sMsg) 5S Xn?
{ _!;Me )C
System.err.println(sMsg); 1Q;}zHd
} 0<"k8 k@J
<tpmUA[]
'crlA~&#/
public static void log(int sMsg) c5q9LQ/
{ "]'?a$\ky:
System.err.println(sMsg); yw[#
} !?f5>Bl
} _EnwME{@
C$Lu]pIL*
r0t^g9K0
/* pA.J@,>`}
**TestMethod.java 3uU]kD^
*/ uJx"W
package NetFox; 8 a!Rb-Q:
,jA)wJ
R2etB*k6[
public class TestMethod { k 4/D8(OXw
j.~!dh$mg
(Q[fS:U
public TestMethod() 76tdJ!4Z
{ ///xx/weblogic60b2_win.exe \y6OUM2y
try{ /[:dp<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZN"j%E{d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LZPuDf~/
SiteFileFetch fileFetch = new SiteFileFetch(bean); f-6vLX\Vu
fileFetch.start(); J]W5[)L
} <9ig?{'
catch(Exception e){e.printStackTrace ();} CO-_ea U(
U~{du;\
sAo& uZ
} W)'*m-I
MUOa@O,
bQe^Px5 !.
public static void main(String[] args) 1}hIW":3Sr
{ *vgl*k?)
new TestMethod(); s &Dg8$
} NC&DFJo
} A,i75kd
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