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)); OnhR`
} mU
for(int i=0;i<nEndPos.length-1;i++) 3ZI:EZ5
{ cNN0-<#c
nEndPos = nStartPos[i+1]; WnOvU<Z <
} 'Z:wEt!
nEndPos[nEndPos.length-1] = nFileLength; KFRf5^%
} J"@X>n
} ';!-a]N
w^=(:`
54B`T/>R:E
//启动子线程 t)uxW 7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kr@!j@j$
for(int i=0;i<nStartPos.length;i++) 3,`M\#z%K
{ q317~z_nl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CrSBN~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N-t"CBTO
nStartPos,nEndPos,i); N=7iQ@{1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sdiWQv
fileSplitterFetch.start(); _sZ&=-FR
} w\UAKN60
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =,C]d~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~kj96w4eAR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?m+];SJk
nEndPos = " + nFileLength); wjZ Q.T!
// fileSplitterFetch[nPos.length-1].start(); Gy;Fe=
zGNW5S9G
mlLqQ<
//等待子线程结束 'n1$Y%t
//int count = 0; .{ZJywE<
//是否结束while循环 J7C?Z
boolean breakWhile = false; (C1~>7L
CE!cZZ
>,tJq%
while(!bStop) SS24@:"{
{ Slj U=,
write_nPos(); i(.V`G=
Utility.sleep(500); A.@wGy4
breakWhile = true; _cC1u7U9
xf8[&?
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for(int i=0;i<nStartPos.length;i++) S:Jg#1rww-
{ ]=ZPSLuEm%
if(!fileSplitterFetch.bDownOver) 'h7x@[|
{ ,3c25.,*
breakWhile = false; /er{sKVX<
break; Q[aF"5h%
} k3e6y
} 6Vncr}
if(breakWhile) ^i2>Ax&T
break; EVBOubV
;DhAw1
'Z=_zG/RX
//count++; vM]5IHqeE
//if(count>4) 0%%y9;o
// siteStop(); E.sZjo1
} -q[x"Ha%
rBU)@IpDG
.qKfhHJ
System.err.println("文件下载结束！"); o8H\l\(
} 98| v.d
catch(Exception e){e.printStackTrace ();} FGie*t
} TQ:e! 32
\kf n,m
PC+Soh*
//获得文件长度 ?Q+*[YEJ5
public long getFileSize() 0UW_ Pbh6
{ .w _BA)
int nFileLength = -1; NS""][#
try{ gdoaXw;Sy
URL url = new URL(siteInfoBean.getSSiteURL()); 3Nwix_&S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p:$kX9mT&
httpConnection.setRequestProperty("User-Agent","NetFox"); s-(c-E09
_Ve)M%
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int responseCode=httpConnection.getResponseCode(); w1(5,~OB
if(responseCode>=400) ;&f(7 Q+T_
{ S 1^t;{"
processErrorCode(responseCode); g.blDOmlc
return -2; //-2 represent access is error KHx;r@{<
} 1*$6u5.=F
:is2 &-|x
|uz\XK
String sHeader; nUVk;0at
w-$iKtb.
N!ay#V
for(int i=1;;i++) ,UC|[-J
{ m\CU,9;;(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6R8>w,
//Utility.log(in.readLine()); :;hX$Qz
sHeader=httpConnection.getHeaderFieldKey(i); !>ZBb\EyK
if(sHeader!=null) fx4#R(N
{ ]q4LNo
if(sHeader.equals("Content-Length")) ZREy I(_
{ {Y=k`t,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q4Bw5~n
break; *?C8,;=2r
} 0-aaLC~Z>
} ~;pP@DA
else B0p;Zh
break; _3N,oCRm
} T][c^K*
} l+@k:IK
catch(IOException e){e.printStackTrace ();} wu11)HFL|z
catch(Exception e){e.printStackTrace ();} -|s%5p|
uPN^o.,/.
_D@QsQ_Z
Utility.log(nFileLength); } _];yw
Wd(|w8J{a
ZAeJTCCk
return nFileLength; ]9'F<T= $_
} v0(}"0
3D5adI<aq"
!>!jLZ0
//保存下载信息（文件指针位置） ubsv\[:C
private void write_nPos() g`C"t3~%S
{ =B'Yx
try{ i$}G[v<4
output = new DataOutputStream(new FileOutputStream(tmpFile)); )+hJi/g
output.writeInt(nStartPos.length); aO?KRn
for(int i=0;i<nStartPos.length;i++) 5T9[a
{ q o-|.I
// output.writeLong(nPos); uh#E^~5S
output.writeLong(fileSplitterFetch.nStartPos); a #s Nd
output.writeLong(fileSplitterFetch.nEndPos); <;>k[P'
} [; $:Lr
output.close(); I7SFGO
} OEzSItAI/[
catch(IOException e){e.printStackTrace ();} )k[XO
catch(Exception e){e.printStackTrace ();} `WxGU
} ,1!Y!,xy
Wnp[8IEU
!B{(EL=g
//读取保存的下载信息（文件指针位置） 1cMdoQ
private void read_nPos() hBcklI
{ Dp#27Yzc
try{ s(s_v ?k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }TuMMO4+
int nCount = input.readInt(); 1rue+GL
nStartPos = new long[nCount]; CN-4FI)1D9
nEndPos = new long[nCount]; ?}W#j
for(int i=0;i<nStartPos.length;i++) -;HZ!Lf
{ CI \O)iB
nStartPos = input.readLong(); Bd;EI)JT
nEndPos = input.readLong(); $:-C9N29
} yDe*-N\'W
input.close(); L"?4}U:
} ?;(!(<{
catch(IOException e){e.printStackTrace ();} JJM!pD\h
catch(Exception e){e.printStackTrace ();} 0|0IIgy
} ,m7Z w_.
9!2$?xqym
-sle7k
private void processErrorCode(int nErrorCode) zH~g5xgh
{ Aq(,
System.err.println("Error Code : " + nErrorCode); 6"rS?>W/mO
} FcOrA3tt
|\"%Dy[m
i*09m^r
//停止文件下载 \Km+>G
public void siteStop() 7<2?NLE8*
{ eCg|@d%D
bStop = true; lD_iIe~c
for(int i=0;i<nStartPos.length;i++) v] Xy^7?
fileSplitterFetch.splitterStop(); n4"xVDL
h4ghMBo%
eSMno_Gt3
} ^;\6ju2
} .>y3`,0h
//负责部分文件的抓取 +_f813$C
**FileSplitterFetch.java *_Pkb.3R
*/ jlUT9Zp
package NetFox; 8jLO-^X<<
s>>lf&7
,d=Dicaz
import java.io.*; RzLeR%O
import java.net.*; Z%r8oj\n
-*?{/QmKb
:4"b(L
public class FileSplitterFetch extends Thread { M[R'
I;P!
$"=0{H.?
String sURL; //File URL w%6 L"
long nStartPos; //File Snippet Start Position *iPBpEWC
long nEndPos; //File Snippet End Position d+8|aS<A
int nThreadID; //Thread's ID [t5Dd
boolean bDownOver = false; //Downing is over )hK;27m4
boolean bStop = false; //Stop identical UC00zW<Z@"
FileAccessI fileAccessI = null; //File Access interface 3+M+5
f-}_
>Y:veEa6v6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9!D c=
{ :{Iv ]d
this.sURL = sURL; U/rFH9e$
this.nStartPos = nStart; '}P$hP_d
this.nEndPos = nEnd; h#|Ac>fz
nThreadID = id; sNC~S%[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VOp+6ho<
} -N2m|%B
-PiZvge
%9t=Iu*
public void run() .8CfCRq
{ FvBnmYnW
while(nStartPos < nEndPos && !bStop) %-NG eN8
{ <bBgevL+_K
GIUyW
mi sPJO&QD
try{ DJRr
URL url = new URL(sURL); Pj*"2 LBW#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 93Qx+oK]
httpConnection.setRequestProperty("User-Agent","NetFox"); Jqt|'G3
String sProperty = "bytes="+nStartPos+"-"; jouT9~[L'
httpConnection.setRequestProperty("RANGE",sProperty); 0:>C v<N
Utility.log(sProperty); :HN\A4=kc(
Ng1[y4R}
X,+N/nku
InputStream input = httpConnection.getInputStream(); LO,k'gg<
//logResponseHead(httpConnection); BOW`{=
Xm.["&
e= _7Q.cn
byte[] b = new byte[1024]; |\q@XCGei
int nRead; J)=Ts({
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =Xb:.
{ ,V=]QHcg
nStartPos += fileAccessI.write(b,0,nRead); 95 X6V
//if(nThreadID == 1) KWT[b?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DGx<Nys@B
} "& q])3h=
J`A )WsKkb
xgB-m[Xi
Utility.log("Thread " + nThreadID + " is over!"); G/}nwj\
bDownOver = true; K6oQx)|
//nPos = fileAccessI.write (b,0,nRead); A)o%\j
} +}!FP3KgT
catch(Exception e){e.printStackTrace ();} AaJnRtBS~
} xy<)zKp
} \F),SL
_~E_#cNn
_VAX~Y]
//打印回应的头信息 ltG|#(
public void logResponseHead(HttpURLConnection con) k|_LF[*Z
{ ^9*Jz{e
for(int i=1;;i++) SV_b(wP9
{ nA XWbavY
String header=con.getHeaderFieldKey(i); @?<1~/sfL
if(header!=null) 7.1FRxS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )m$i``*<
Utility.log(header+" : "+con.getHeaderField(header)); C]%}L%,
else o_%gFV[q
break; qu0dWgK
} q8fnUK?i
} G!m;J8#m(
`v1~nNoY
ndB*^nT
public void splitterStop() -D,kL
{ JAcNjzL
bStop = true; e!O:z
} n%:&N
;"DI)hdz
&<S]=\
} hvU\l`m
{}v<2bS
}VXZM7@u
/* /7XVr"R
**FileAccess.java u1i ?L'
*//文件访问(定位，写) ++M%PF [ {
package NetFox; Z"g6z#L&
import java.io.*; bjGQ04da
1 gx(L*y,
5_Opx=
public class FileAccessI implements Serializable{ ALnE[}N6,
5Lm<3:7Q+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3r,^is
RandomAccessFile oSavedFile; @ Yzj
long nPos; 91j.%#[v'
t_ZWd#x+;
3k?|-js
public FileAccessI() throws IOException v?(9ZY]
{ >>HC|
this("",0); >qjV(_?F-
} [i)G:8U
9jTm g%
5!^DKyw:
public FileAccessI(String sName,long nPos) throws IOException CaqMLi%
{ lC(g&(\{
oSavedFile = new RandomAccessFile(sName,"rw"); QF`o%mI
this.nPos = nPos; uNRT@@oCq
oSavedFile.seek(nPos); /:@X<
} Luu.p<
Z:s:NvFX
Pi:=0,"XOp
public synchronized int write(byte[] b,int nStart,int nLen) 0}y-DCuQ
{ |F^h>^ x
int n = -1; _a~-B@2g
try{ >^hy@m
oSavedFile.write(b,nStart,nLen); h|t\rV^
n = nLen; -z$&lP]
} #^oF^!
catch(IOException e) (qXl=e8
{ &C7HG^;W9
e.printStackTrace (); b9@VD)J0E
} \H5{[ZUn
VyL|d^'f_
J?N9*ap)
return n; o@g/,V $
} s.G6?1VXlY
j8"2K^h=
1|zy6
} 5uufpvah
!2Q>
b5Pakz=jNM
/* 9F"Q2^l'
**SiteInfoBean.java /*yPy?
*/ a2N4Jg@
package NetFox; 4\%XC F!
mrz@Y0mgL
ngHPOI16
public class SiteInfoBean { 6$^dOJ_"
Ghpk0ia%d
eEG]JH
private String sSiteURL; //Site's URL gELb(Y\ak
private String sFilePath; //Saved File's Path <"XDIvpc%L
private String sFileName; //Saved File's Name F"M$ "rC]
private int nSplitter; //Count of Splited Downloading File %/x%hs;d
FI$#x%A
jB-)/8.qk
public SiteInfoBean() CD+2 w cy
{//nSplitter的缺省值为5 h8lI#Gs
//default value of nSplitter is 5 pe1_E KU
this("","","",5); B 8ycr~
} ~NtAr1
qxe%RYdA'j
qW6}^aa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SMdkD]{g
{ hMiuv_EO!
sSiteURL= sURL; b_JW3l
sFilePath = sPath; 9&`ejeD
sFileName = sName; )c$)am\I{
this.nSplitter = nSpiltter; >av.pJ(>
';z5]O~
-'OO6mU
} H^no&$2`1
GxIw4m9
sB,>4*Zd
public String getSSiteURL() [o,S.!W8
{ X519} l3
return sSiteURL; Qb;5:U/x
} g6. =(je
\!tS|h
Lx"a#rZ
public void setSSiteURL(String value) mTW@E#)n
{ `1[GY){?)
sSiteURL = value; bu2'JIDR
} t[ZumQ@HC
!F|iL
!B3lsXLSY
public String getSFilePath() hoQ?8}r:
{ #`0iN+qh
return sFilePath; 7o4 vf~
} rGe^$!QB
^{W#ut>IN
cs%NsnZ
public void setSFilePath(String value) '0xJp|[xVP
{ (Q$]X5L
sFilePath = value; }bs2Rxkh
} cCjpQ
e]+ [lq\p@
DjT ekn
public String getSFileName() U "qO&;m
{ -0)So
return sFileName; ~"*;lT5KX
} B43o_H|s
r]=3aebR.
j{nkus2
public void setSFileName(String value) Vo%UiVHy
{ diLjUC`69
sFileName = value; ,QpDz{8
} d\ &jl`8*
+(3PY e\
]rh)AE!Y(
public int getNSplitter() "iof -b=ys
{ 8bX\^&N
return nSplitter; \?} {wh8
} A*h)p@3t<
rr[9sk`^H
bz~-uHC
public void setNSplitter(int nCount) _l?5GLl_F$
{ f-\l<o(
nSplitter = nCount; wBcDL/(>
} ~~ON!l9n
} Lh &L5p7
c3lfmTT6^
|yI?}zyR
/* w?AE8n$8
**Utility.java Oz9k.[j(
*/ ubhem(p#
package NetFox; oh;F]*k6
b>%I=H%g
EMH?z2iGd
public class Utility { `.dTkL
^}8_tZs8\
f ( `.q
public Utility() )^!-Aj\x
{ U[S;5xeF.j
Ze$:-7Czl
7l Aa6"Y68
} P|.KMtG
8IC((
//线程睡眠 nm'm*sU\
public static void sleep(int nSecond) @D"1}CW
{ S$"A[
try{ 7$GP#V1r/
Thread.sleep(nSecond); f|VP_o<
} CRWO R pP
catch(Exception e) )m[!HE`cZ
{ PyHE>C%
e.printStackTrace (); !*%3um
} !9o8v0ZI
} -T{~m6
gr=ke #
//日志 hJ:Hv.{`)W
public static void log(String sMsg) p,D/ Pb8
{ yB.6U56
System.err.println(sMsg); c2"eq2'BS
} kXX RMR
raJyo>xXb5
`T9<}&=!
public static void log(int sMsg) ]Wa,a T'
{ 4 qW)R{%
System.err.println(sMsg); n?,fF(
} bM^'q
} 72-@!Z0e
`hlyN]L
y+:<
/* cDTDim1F
**TestMethod.java GW $iK@
*/ <{-DYRiN
package NetFox; 6!Isz1.re
N7#GK]n%/}
YgWnPp
public class TestMethod { "Pys3=h
"Ln\ZYB]
C1G Wi4)
public TestMethod() SwP h-6
{ ///xx/weblogic60b2_win.exe y6jTT%
try{ %n}]$ d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M(3E b;`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6 *8Ge
SiteFileFetch fileFetch = new SiteFileFetch(bean); % 9WWBxS
fileFetch.start(); *`jEg=)
} ZRxB"a'
catch(Exception e){e.printStackTrace ();} i&LbSxUh9
3 oWCQ
7SqsVq`[~
} Tf0#+6 1>
wOk:Q4OjL
Yp ? 2<
public static void main(String[] args) |R[m&uOib
{ YT:5J%"
new TestMethod(); .HtDcGp
} )O&$-4gL'
} aVtwpkgZ
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