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)); /(s |'"6
} I(~([F2
for(int i=0;i<nEndPos.length-1;i++) nzaDO-2!
{ A2ye ^<-C.
nEndPos = nStartPos[i+1]; (}X5*BB&
} qWr=Oiu
nEndPos[nEndPos.length-1] = nFileLength; F!#)l*OX;
} tjtvO@?1-
} q$"u<
3'.3RKV
n}Z%D-b$
//启动子线程 vOlfyH>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9]=J+ (M
for(int i=0;i<nStartPos.length;i++) Y[7prjd
{ }>@SyE'Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q#AEu xI1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3<XuJ1V&
nStartPos,nEndPos,i); _=I1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ASy?^Jrs5
fileSplitterFetch.start(); `"CA$Se8
} 72~L ?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ||X3g"2W9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~2rQ80_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >A{Dpsi\
nEndPos = " + nFileLength); +g?uvXC&
// fileSplitterFetch[nPos.length-1].start(); Gz{%Z$A~o
ri4z^1\
Fvk=6$d2
//等待子线程结束 ddN(L`nd
//int count = 0; .\$A7DD+A
//是否结束while循环 K.QSt
boolean breakWhile = false; hGD@v{/
_(J#RH
k vZw4Pk
while(!bStop) [#Apd1S_
{ eV}"L:bgJ
write_nPos(); npzp/mcIe)
Utility.sleep(500); h'em?fN(
breakWhile = true; =At" Q6-O
tm5{h{AM
A^).i_&#
for(int i=0;i<nStartPos.length;i++) !aUYidd
{ L<=Dl
if(!fileSplitterFetch.bDownOver) ]CLM'$
{ 2R,} j@
breakWhile = false; KJyCfMH&:@
break; 1LS1 ZY
} vW eg1
} _Vp"G)1Y
if(breakWhile) R/"f
break; ;8PO}{rD
stK}K-=`
_ab8z]H
//count++; U)f('zD
//if(count>4) nxhlTf>3
// siteStop(); P]n0L4c
} :qxWANUa
mWZP.w^-
"|I.j)
System.err.println("文件下载结束！"); C~4SPCU
} J|{50?S{^
catch(Exception e){e.printStackTrace ();} v|~=rvXFC
} EGgw#JAi#t
<vWP_yy
TO89;O
//获得文件长度 3}s]F/e
public long getFileSize() (bv{17K
{ VK*_pEV,}
int nFileLength = -1; .F$}a%
try{ uQc("F
URL url = new URL(siteInfoBean.getSSiteURL()); Mm*V;ADF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Tar?&C:
httpConnection.setRequestProperty("User-Agent","NetFox"); &,<,!j)Jr
!;8Y?c-D
{.kIC@^O
int responseCode=httpConnection.getResponseCode(); er24}G8
if(responseCode>=400) oS$7k3s fj
{ 6M&ajl`o
processErrorCode(responseCode); 4vi?9MPz
return -2; //-2 represent access is error ]cP%d-x}
} 4+>yL+sC%v
:k?`gm$
{+#{Cha
String sHeader; \Y"S4<"R
\?t8[N\_[(
>b"@{MZ@t
for(int i=1;;i++) : 8>zo
{ `AE6s.p?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Sak^J.~G[
//Utility.log(in.readLine()); ij:a+T
sHeader=httpConnection.getHeaderFieldKey(i); 0~ nCT&V
if(sHeader!=null) 7#+Ih-&EQ
{ `:7r5}(^
if(sHeader.equals("Content-Length")) |sr\SCx
{ 5@1h^wv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jt}oq%Bf
break; ]vB^%
} Pi=FnS
} <2@t~9
else 3HXeBW
break; ^_v94!a9
} i_m&qy<v
} wuY-f4
catch(IOException e){e.printStackTrace ();} lwt,w<E$
catch(Exception e){e.printStackTrace ();} 6!0NFP~b
j%3$ytf|p
KL?<lp"
Utility.log(nFileLength); ?MSZO]Q4+
4w%hvJ
5K9W5hA:D
return nFileLength; ynra%"sd
} }Y.@:v j
j,].88H
}P%gwgPK
//保存下载信息（文件指针位置） 4J,6cOuW4
private void write_nPos() =CFg~8W
{ +,"[0RH
try{ ,e$RvFB
output = new DataOutputStream(new FileOutputStream(tmpFile)); yg}L,JJU<
output.writeInt(nStartPos.length); Rq|5%;1
for(int i=0;i<nStartPos.length;i++) M.5F|7
{ 1c"s+k]9
// output.writeLong(nPos); B> i^w1
output.writeLong(fileSplitterFetch.nStartPos); O<!^^7/h0
output.writeLong(fileSplitterFetch.nEndPos); 6T~+vT
} |1ry*~
output.close(); _d~GY,WTdO
} 5C*Zb3VG4
catch(IOException e){e.printStackTrace ();} q{*[uJ}Xc"
catch(Exception e){e.printStackTrace ();} ^{yb4yQ 0
} vQXF$/S
gHUW1E
@:hWahMy
//读取保存的下载信息（文件指针位置） }1CO>a<
private void read_nPos() PTpCiiA@
{ |'i ?o
try{ coaJDg+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (ce)A,;
int nCount = input.readInt(); [uie]*^
nStartPos = new long[nCount]; 3S^Qo9S
nEndPos = new long[nCount]; c?xeBC1-
for(int i=0;i<nStartPos.length;i++) P'_ aNU
{ 4byh,t
nStartPos = input.readLong(); (#je0ES
nEndPos = input.readLong(); q{,yas7}
} +W>tdxOh
input.close(); $\4Or
} >>J!|
catch(IOException e){e.printStackTrace ();} =|-xj h
catch(Exception e){e.printStackTrace ();} QIN# \
} @J@bD+Q+0
I GcR5/3
d9 8pv%
private void processErrorCode(int nErrorCode) S!}pL8OE
{ gJOswN;([
System.err.println("Error Code : " + nErrorCode); _x#r,1V+D
} ;NJM3g0I
Git2Cet
y7*^H
//停止文件下载 d7c m?+
public void siteStop() )^^}!U#|e
{ H~*[v"
bStop = true; Q([g1?F9*
for(int i=0;i<nStartPos.length;i++) wVs|mG"
fileSplitterFetch.splitterStop(); ',RR*{I
/ dn]`Ge)
.Qj`_q6=
} 2gjA>ET`N
} \@n/L{}(@
//负责部分文件的抓取 9Bmgz =8
**FileSplitterFetch.java z!j`Qoh?V9
*/ }W%}_UT
package NetFox; [ 06B)|s
PsD]gN5"
Y!s/uvRI
import java.io.*; qm}7w3I^
import java.net.*; 8|Y^z_C
Z=sAR(n}~
X}bgRzj
public class FileSplitterFetch extends Thread { kp;MNRc
`^N;%[c`z
Q{Bj(f
String sURL; //File URL S"Zs'7dy`
long nStartPos; //File Snippet Start Position aH$*Ue@Q
long nEndPos; //File Snippet End Position Ap>n4~
int nThreadID; //Thread's ID D{z=)'/F
boolean bDownOver = false; //Downing is over en~(XE1
boolean bStop = false; //Stop identical 'Ph;:EMj
FileAccessI fileAccessI = null; //File Access interface ;[zx'e?!
XJ NKM~
(}qLxZ/U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KJkcmF}Q
{ 3i$AR
this.sURL = sURL; 2Uk8{d
this.nStartPos = nStart; ,[hJi3xM
this.nEndPos = nEnd; XAFTLNV>
nThreadID = id; D 7E^;W)H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BR%:`uiQ<
} fu&]t8MJC
nW%c95E
(jyJ-qe
public void run() Mo<p+*8u:
{ }w@nZG ^&
while(nStartPos < nEndPos && !bStop) aH#|LrdJ
{ +%~g$#tlJo
K^vMIoh
#sHP\|rA
try{ Yb\36|
URL url = new URL(sURL); Zj0&/S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JZ7-? o
httpConnection.setRequestProperty("User-Agent","NetFox"); ixkg,
String sProperty = "bytes="+nStartPos+"-"; g/yXPzLU
httpConnection.setRequestProperty("RANGE",sProperty); 1f:k:Y9i
Utility.log(sProperty); [)=FZF6kG
Aws TDM
vtT:c.~d
InputStream input = httpConnection.getInputStream(); ;g*6NzdA
//logResponseHead(httpConnection); !14z4]b
3IxT2@H)
/L 4WWQ5
byte[] b = new byte[1024]; ,O+7nByi[V
int nRead; w?C\YKF7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M>#{~zr
{ EIfrZg7R
nStartPos += fileAccessI.write(b,0,nRead); 4c yv 8
//if(nThreadID == 1) ]9:G3vq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WveFB%@`;
} td~3N,S
\NqC i'&
9+']`=a:
Utility.log("Thread " + nThreadID + " is over!"); =EJ"edw]%0
bDownOver = true; .,,73"
//nPos = fileAccessI.write (b,0,nRead); )Fw)&5B!
} 8FITcK^
catch(Exception e){e.printStackTrace ();} qGqu/$bh
} m @%|Q;
} U{Z>y?V/
;z>YwRV
,L;vN6~
//打印回应的头信息 wGH@I_cy>
public void logResponseHead(HttpURLConnection con) UK,P?_e
{ URgF8?n
for(int i=1;;i++) =)8Ct
{ ~e<<aTwN
String header=con.getHeaderFieldKey(i); 7w*&Yg]
if(header!=null) /["T#`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i.]zq
Utility.log(header+" : "+con.getHeaderField(header)); I1~g?jpH
else jlBCu(.,_
break; %K7}yy&9C
} UJ[a&b
} d#Ajb
-wfV
[Bo$?
public void splitterStop() 3XtGi<u
{ YP,PJnJU8
bStop = true; j+hoj2(
} rYQ@"o0/Y
M'iKk[Hjfx
r `dU (T!
} ?xZmm%JF
rUjr'O0
E,@UM$alP
/* :F=nb+HZ
**FileAccess.java _4$DnQ6&
*//文件访问(定位，写) F.D1;,x
package NetFox; [!mjUsut*
import java.io.*; qGCg3u6
a7G2C oM8
RzQS@^u*F0
public class FileAccessI implements Serializable{ ;r"B?]JO
I;H9<o5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d A{Jk
RandomAccessFile oSavedFile; %)Dd{|c
long nPos; /8\&f%E
0K0=Ob^(e
|9]K:A
public FileAccessI() throws IOException WI_mJ/2
{ W%K8HAP"
this("",0); !p2,|6Y`y
} zqr%7U
5O ;^Mk|
$#3<rcOq
public FileAccessI(String sName,long nPos) throws IOException '<S:|$$
{ \3?;[xD
oSavedFile = new RandomAccessFile(sName,"rw"); }p?V5Qp
this.nPos = nPos; 9?chCO(@
oSavedFile.seek(nPos); >Eg.c
} 9= $,]M
_kX/LR"L+
wg0.i?R-]
public synchronized int write(byte[] b,int nStart,int nLen) <L/vNP
{ h_GBx|c
int n = -1; {<[tYZmj.
try{ .t[ZXrd|0
oSavedFile.write(b,nStart,nLen); C+m^Z[
n = nLen; 1'm`SRX#e
} (A fbS=[
catch(IOException e) N%|Vzc
{ JD`;,Md
e.printStackTrace (); _XNR um4
} 8!Mzr1:
~V"cLTj"
6ri?y=-c
return n; NG!cEo:2aa
} )X!DCL:16
AYu'ptDNr
\If!5N
} zn;Hs]G
^O Xr: P
wp*&&0O!
/* $0S#d@v}
**SiteInfoBean.java .P:f
*/ Sb9=$0%\
package NetFox; q '{<c3&
V&j.>Y
{e[pSD6
public class SiteInfoBean { <Bb<?7q$ld
2{]S_. zV
?"<r9S|[O
private String sSiteURL; //Site's URL 0H&U=9'YT
private String sFilePath; //Saved File's Path 9eN2)a/
private String sFileName; //Saved File's Name R ms01m>Y
private int nSplitter; //Count of Splited Downloading File Pzm!`F^r}
f'`nx;@X
LXu"rfp
public SiteInfoBean() E,D:D3O
{//nSplitter的缺省值为5 ;ko[(eFN@
//default value of nSplitter is 5 xAd>",=~
this("","","",5); BXK::M+
} fByh";<`P
['Y+z2k
$sL|'ZMbS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a[74%L?
{ YK?*7
sSiteURL= sURL; 3+8"
sFilePath = sPath; F`BgKH!
sFileName = sName; |`Oa/\U
this.nSplitter = nSpiltter; o&XMgY~
_]D#)-uv}C
,7fc41O3V
} nc\C4g
gR-Qj
0n<(*bfW
public String getSSiteURL() h\u0{!@}
{ EB29vHAt~
return sSiteURL; A M1C $
} 4`UL1)A]
>\?z37:T
^0s\/qyqm
public void setSSiteURL(String value) g",wkO|
{ `Ge+(1x
sSiteURL = value; 4QjWZ Wl
} aZawBU.:
s7.p$r
^0`<k
public String getSFilePath() /J[H5uA
{ 0Y6q$h>4
return sFilePath; jr[<i\!
} ~gfA](N
1(%>`=R8
uK;K{
public void setSFilePath(String value) 4j=<p@
{ yWv<A^C&
sFilePath = value; Y[iDX#
} SvX=isu!.
OBI+<2`Oc
t":W.q<
public String getSFileName() 8NaL{j1`
{ jNe(w<',P
return sFileName; 3qAwBVWa
} {*?sVAvj
+ %MO7vL
9@#h}E1$
public void setSFileName(String value) 2/yXY_L
{ Wa[x`:cT?u
sFileName = value; <2)s<S.;
} `%t$s,TiP
cS D._"P
@,x_i8
public int getNSplitter() 4pmTicA~
{ Pv/Pww\
return nSplitter; MvFM,
} 0T9@,scY
<#+oQ>5s
0W T#6D
public void setNSplitter(int nCount) yaH Trh%
{ F . K2
nSplitter = nCount; y4xT:G/M
} KqM!!
} QU^/[75Ea0
gEZwW]r-
"wA0 LH_
/* \8;Qv
**Utility.java _4P;+Y
*/ s<A*[
package NetFox; LXHwX*`Y
T*h!d(
T)WZ_bR
public class Utility { 5cD XWF
HQq`pG%m6
`IEq@Wr#$!
public Utility() <Ctyht0c.
{ <jbj/Q )"
s~S?D{!
+yzcx3<
} BJ~ivT<
c]A Y
//线程睡眠 B|cA[
public static void sleep(int nSecond) x!'7yx
{ {mNdL J
try{ ]EB6+x!G
Thread.sleep(nSecond); ]]>nbgGn#
} BjM+0[HC
catch(Exception e) mO#I nTO
{ +0VG[c\8
e.printStackTrace (); @ru<4`h
} |<sf:#YzY&
} _1sP.0 t
(nGkZ}p
//日志 H{ZLk,
public static void log(String sMsg) ylk{!
{ j5kA^MTG
System.err.println(sMsg); A:/}`
} kEO1TS
|Eb&}m:E$
4<u;a46Z#M
public static void log(int sMsg) NdZ)[f:2
{ C1 W>/?XC
System.err.println(sMsg); Y+FP
} XM$GQn]B
} 9qEOgJ
dgXg kB'
#zxd;;p3
/* @d&g/ccMxd
**TestMethod.java iAK/d)bq
*/ %*6RzJO6
package NetFox; {ih:FcI
{gsW(T>)
J;~E<_"Hn
public class TestMethod { D ZVXz|g
mmHJh\2v
0 sZwdO
public TestMethod() [UoqIU
{ ///xx/weblogic60b2_win.exe `$at9
try{ $.a|ae|K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6+iK!&+=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y1iX!m~)
SiteFileFetch fileFetch = new SiteFileFetch(bean); PcB{=L
fileFetch.start(); YZ< NP
} X@!X6j
catch(Exception e){e.printStackTrace ();} -,^WaB7u\
`y2ljIWJ
9\AS@SH{^T
} 6}ftBmv
3T1P$E" m
Wab.|\c
public static void main(String[] args) EL7T'zJ$
{ OF8WDo`
new TestMethod(); Zi/-~')E
} @bT3'K-4
} 9:-T@u
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