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)); .t[ZXrd|0
} .+L_!A
for(int i=0;i<nEndPos.length-1;i++) l!V| T?
{ 4Olv8nOe<
nEndPos = nStartPos[i+1]; aw%vu
} )"jn{%/t
nEndPos[nEndPos.length-1] = nFileLength; ]{+M>i[
} [k7N+W8
} fUKdC\WL
LY:?OGh
?mfWm{QTt
//启动子线程 8!Mzr1:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,xe@G)a
for(int i=0;i<nStartPos.length;i++) %aE7id>v6
{ (`.qG &6p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G:C6`uiy`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8kM0
nStartPos,nEndPos,i); <ZC^H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '# IuY
fileSplitterFetch.start(); !XA%[u
} p2DNbY\]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), as|c`4r\O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;6 6_G Sjz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }rA+W-7
nEndPos = " + nFileLength); mYOdBd
// fileSplitterFetch[nPos.length-1].start(); )LrCoI =|
( WtE`f;Q
_6S b.9m
//等待子线程结束 >c\v&k>6.
//int count = 0; .O%1)p
//是否结束while循环 CSqb)\8Oi*
boolean breakWhile = false; akc"}+-oX
)P9{47
{G1aAM\Hz
while(!bStop) 1L=Qg4 H
{ s]<r
write_nPos(); v\9,j
Utility.sleep(500); cU5"c)$'
breakWhile = true; 2T(,H.O
hB$Y4~T%
m/c&/6nk
for(int i=0;i<nStartPos.length;i++) 9_A0:S9Z
{ /xm#:+Sc
if(!fileSplitterFetch.bDownOver) :;*#Qh3"
{ kPX2e h
breakWhile = false; pM'IQ3N
break; 5v>{Z0TE[6
} qwNKRqT
} 3auJ^B}
if(breakWhile) NuS|X
break; {}J@+Zsi
(06Vcqg
;ko[(eFN@
//count++; MLD>"W
//if(count>4) e]*=sp!T
// siteStop(); _QMHPRELk
} _?]BVw
fByh";<`P
l88a#zUQDN
System.err.println("文件下载结束！"); &c<}++'h
} Q#ZD&RZ9.
catch(Exception e){e.printStackTrace ();} yK%GsCJd:
} <X I35\^
4>"cc@8&~
4lh
//获得文件长度 p-'6_\F.Ke
public long getFileSize() q4.dLU,1
{ 'f?&EsIV?
int nFileLength = -1; eFj6p<
try{ _z(5e
URL url = new URL(siteInfoBean.getSSiteURL()); Ad`[Rt']kI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B`?N0t%X
httpConnection.setRequestProperty("User-Agent","NetFox"); rv%ye H
C=dx4U~
*n*N|6+
int responseCode=httpConnection.getResponseCode(); PZ!dn%4jy
if(responseCode>=400) yhtvr5z1
{ bhqq
processErrorCode(responseCode); I~]Q55
return -2; //-2 represent access is error (XG[_
} Q+!0)pG5#
Oa\`;
rTsbP40
String sHeader; +>!B(j\gx
O{B e )E~
^0s\/qyqm
for(int i=1;;i++) J%\~<_2ny
{ x'@32gv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y0X"Zw
//Utility.log(in.readLine()); -#S)}NEn
sHeader=httpConnection.getHeaderFieldKey(i); CEX}`I*-
if(sHeader!=null) 4g6ksdFQ
{ ?lc[hH
if(sHeader.equals("Content-Length")) r}y[r}vk
{ 7dlKdKH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N7~)qqb
break; rZ!Yi*? f
} :<N6i/
} RhV:Z3f`6
else {KU.
break; X@yr$3vC
} e:$7^Y,U/
} /Oggt^S
catch(IOException e){e.printStackTrace ();} W) 33;E/}
catch(Exception e){e.printStackTrace ();} K{zCp6
2GiUPtO&Gj
FM9X}%5nu9
Utility.log(nFileLength); ;Y@!:p-H
%l8*t$8
4#@W;'
return nFileLength; UKKSc>D1
} sw41wj
tIyuzc~U
Y3P.|
//保存下载信息（文件指针位置） ];pf
private void write_nPos() p- "Z'$A`
{ Vedyy\TU
try{ $*AC>i\
output = new DataOutputStream(new FileOutputStream(tmpFile)); r)6uX
output.writeInt(nStartPos.length); >k&8el6h
for(int i=0;i<nStartPos.length;i++) {*?sVAvj
{ @q> ktE_
// output.writeLong(nPos); V\@jC\-5Vt
output.writeLong(fileSplitterFetch.nStartPos); N;Z`%&
output.writeLong(fileSplitterFetch.nEndPos); *?^Z)C>
} Sg.+`xww3
output.close(); e$Xq
} C5PmLiOHY>
catch(IOException e){e.printStackTrace ();} 4-7kS85
catch(Exception e){e.printStackTrace ();} |RR%bQ^{
} fjIcB+Z
_e?q4>B)c
]DC;+;8Jc
//读取保存的下载信息（文件指针位置） I!$jYY2
private void read_nPos() Ic[}V0dk
{ 49+ >f
try{ p{ @CoOn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mVv\bl?<
int nCount = input.readInt(); G}!7tU
nStartPos = new long[nCount]; 6o=qJ`m[?
nEndPos = new long[nCount]; xH_A@hf;
for(int i=0;i<nStartPos.length;i++) Lh8bQH
{ =zeFK_S!
nStartPos = input.readLong(); %6NO0 F^
nEndPos = input.readLong(); . ]o3A8
} 2E`~ qn
input.close(); U,Z"G1^
} [ME}Cv`?<E
catch(IOException e){e.printStackTrace ();} u\{qH!?t
catch(Exception e){e.printStackTrace ();} ]Q6+e(:~ZH
} .e`,{G(5q7
?YqJ.F;
.O5LI35,
private void processErrorCode(int nErrorCode) r-RCe3%g%
{ w=f0*$ue+w
System.err.println("Error Code : " + nErrorCode); |Z`M*.d+
} @gt)P4yE
)Qh>0T+(
cS<TmS!
//停止文件下载 Qw24/DJK
public void siteStop() .UM<a Ik
{ t6'61*)|0
bStop = true; D9qX->p
for(int i=0;i<nStartPos.length;i++) ! jbEm8bt
fileSplitterFetch.splitterStop(); _Kc1
Dh2:2Rz=#7
2.[_t/T
} Y%<`;wK=^
} `9.dgV
//负责部分文件的抓取 I2TD.wuIW
**FileSplitterFetch.java mD9STuA$H
*/ 79)A%@YHQQ
package NetFox; B0f_kH~p~
"'['(e+7
:{[<g](
import java.io.*; u5Qp/ag?N
import java.net.*; `S"W8_m
M[ x_#m|
jja{*PZ6H
public class FileSplitterFetch extends Thread { X'cf&>h
r%0pQEl
[NYj.#,oR
String sURL; //File URL IE&_!ce
long nStartPos; //File Snippet Start Position JXpoCCe
long nEndPos; //File Snippet End Position >|wKXz
int nThreadID; //Thread's ID f?,-j>[.=f
boolean bDownOver = false; //Downing is over ~O \}/I28
boolean bStop = false; //Stop identical ?n!lUr$:y
FileAccessI fileAccessI = null; //File Access interface 4\p$4Hs}
tf4*R_6;1$
ecn}iN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :/+>e IE
{ 2 9q?$V(
this.sURL = sURL; +0VG[c\8
this.nStartPos = nStart; A#<vG1
this.nEndPos = nEnd; S8\+XJ
nThreadID = id; aK]7vp+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E@:Q 'g%
} TbOJp
[}z?1Gj;W(
2=>*O
public void run() e#tIk;9Xz
{ nz^nptw
while(nStartPos < nEndPos && !bStop) XJe/tR
{ X]qCS0GD'
GGH;Z WSe
#C4|@7w%
try{ :]'q#$!
URL url = new URL(sURL); d!o.ASL{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _*Pfp+if
httpConnection.setRequestProperty("User-Agent","NetFox"); xJ-*%'(KZ
String sProperty = "bytes="+nStartPos+"-"; 1Yud~[c
httpConnection.setRequestProperty("RANGE",sProperty); cn$5:%IK
Utility.log(sProperty); ji}#MBac
ASR-a't6
wTTRoeJ}
InputStream input = httpConnection.getInputStream(); djUihcqA`
//logResponseHead(httpConnection); lqF>=15
~L~]QN\3
u=%y
byte[] b = new byte[1024]; o~= iy
int nRead; s3seK6x'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !Q!&CG5l
{ dsV ~|D6:
nStartPos += fileAccessI.write(b,0,nRead); 7R: WX:
//if(nThreadID == 1) ozU2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [eyb7\#
} V"O9n[|
H.:9:I[n
KGu= ;
Utility.log("Thread " + nThreadID + " is over!"); `qE4U4
bDownOver = true; J;~E<_"Hn
//nPos = fileAccessI.write (b,0,nRead); /9pbnzn
} W,Ty=:qm*
catch(Exception e){e.printStackTrace ();} _ \l HI
} K5{{:NR$
} QP:9%f>=
.:8[wI_f
mH)OB?+lq
//打印回应的头信息 GMBJjP&R]
public void logResponseHead(HttpURLConnection con) PB+\jj
{ 5C B%=iL{
for(int i=1;;i++) g92dw<$>
{ ;Z*'D}
String header=con.getHeaderFieldKey(i); (-\]A|
if(header!=null) /l^y}o %?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); usy,V"{
Utility.log(header+" : "+con.getHeaderField(header)); UeA2c_ 5
else zj{(p Z1
break; I0iY+@^5
} _lP4}9p
} 7,h3V=^)Q
Qwv '<
9\AS@SH{^T
public void splitterStop() wlrIgn%
{ AFGwT%ZD
bStop = true; KSc~GP_
} j{)~QD?
jB!W2~Z
Y''6NGf
} a%E8(ms37y
M6_-f ;.
r{S=Z~J
/* =UNT.]
**FileAccess.java )pS8{c)E
*//文件访问(定位，写) dQ<(lzS~
package NetFox; 9`BEi(z
import java.io.*; &\k?xN
zw]3Vg{T
Ukc'?p,*
public class FileAccessI implements Serializable{ jn$j^51`C
wWTQ6~Y%d
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '0RRFO
RandomAccessFile oSavedFile; ^X&)'H
long nPos; 4{Udz!
9#Y2`pT
zmb@*/fK
public FileAccessI() throws IOException p![&8i@ym
{ vU}: U)S
this("",0); $6!iBX@
} Sph*1c(R
*Tp]h 0
vTd-x>n
public FileAccessI(String sName,long nPos) throws IOException >jMH#TZaX
{ "15=ET
oSavedFile = new RandomAccessFile(sName,"rw"); ]G*$W+G]
this.nPos = nPos; +i=p5d5
oSavedFile.seek(nPos); C8.W5P[U
} e!Br>^8l
JT)k
:!O><eQw
public synchronized int write(byte[] b,int nStart,int nLen) =Z`0>R`
{ >A($8=+#x
int n = -1; U Du~2%
try{ HN68!v}C|
oSavedFile.write(b,nStart,nLen); cy3M^_5B<
n = nLen; fK_~lGY(
} SA+d&H}Fc
catch(IOException e) 9|=nV|R'6
{ lR@& Z6lw
e.printStackTrace (); W2<3C
} K/|
.&iN(Bd
A"4@L*QV
return n; 3ji:O T
} + |C=ZU
^f|<R8`
-~O/NX
} V#J"c8n
7|Dn+=
lw[<STpD;
/* ([KN*OF
**SiteInfoBean.java XG&K32_fs
*/ X NE+(Bt
package NetFox; }0;Sk(B>
C[8KlD
$XGtS$
public class SiteInfoBean { 0T))>.iu#
{eR9 ;2!
{|6z+vR
private String sSiteURL; //Site's URL gz61FW
private String sFilePath; //Saved File's Path 5B*qbM
private String sFileName; //Saved File's Name $.:3$et@/
private int nSplitter; //Count of Splited Downloading File sPCMckt
|>2:eH
CH;;V3
public SiteInfoBean() tpYa?ZCM
{//nSplitter的缺省值为5 eYEc^nC,c)
//default value of nSplitter is 5 Hku=pr3Gn
this("","","",5); 4RQ5(YTTuR
} o56kp3b)b
~@P)tl>
j=ihbR^]Tl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q2c*.Y
{ N9]xJgTze
sSiteURL= sURL; 4ht\&2&:
sFilePath = sPath; uyT/Xzo3
sFileName = sName; Rp/-Pv
this.nSplitter = nSpiltter; -H\,2FO
O2v.
5pJ*1pfeo
} L~eAQR
bUs|t
t5)J;0/
public String getSSiteURL() TyOH`5D
{ uV~e|X "9s
return sSiteURL; :woa&(wN;1
} <Wy>^<`
*]x_,:R6Ow
a)S7}0|R
public void setSSiteURL(String value) C).2gQ G
{ ce'TYkPM
sSiteURL = value; 0JXqhc9'
} TpP8=8_Lh
<AUWby,"
l!IGc:
public String getSFilePath() ``9 GY
{ 2[up+;%Y
return sFilePath; oT3Y!Y3=<
} #C\4/g?=,
Jqru AW<
>Z\BfH
public void setSFilePath(String value) ]a/'6GbR
{ GZ8:e3ri
sFilePath = value; I7mG/
} <zfKC
;fGx;D
(M`|'o!
public String getSFileName() Ror2qDF
{ LC-)'Z9}5
return sFileName; ]US[5)EL-
} %;O}FyP
s, XM9h>P4
Y8ehmz|g]J
public void setSFileName(String value) H06Bj(Y!
{ G$5m$\K
sFileName = value; ]W) jmw'mo
} \+Y!ILOI
GDPo`#~
HFS+QwHW
public int getNSplitter() jvs[ /
{ .wc = ]
return nSplitter; Jps .;yjk
} ;&?pd"^<_Z
A/ 0qk
daX*}Ix
public void setNSplitter(int nCount) 7&6Y
{ +v15[^F
nSplitter = nCount; R]QpMj%o
} nY^Nbh0
} d 4O
;[6&0!N\
~FUa:KYD
/* k'+}92 o
**Utility.java , Oli
*/ @vs@>CYdz
package NetFox; ~7SH4Cr
J70D+
N5 n>
public class Utility { L2|aHI1'l
0*7*RX
8A{6j
public Utility() 7X'y>\^w^>
{ ;NsO
vWY(%Q,
r4eUZ .8R
} RP` `mI
?_ RYqolz
//线程睡眠 ek)Xrp:2
public static void sleep(int nSecond) 6/2v
{ x / XkD]Hq
try{ R^P_{_I*"
Thread.sleep(nSecond); 8$}OS-
} 2)\vj5<~$
catch(Exception e) t(?<#KUB-
{ 7+XM3
e.printStackTrace (); gfo}I2"
} 'sU)|W(3U
} &" h]y?Q
"mZ.V
//日志 ?R6`qe_F
public static void log(String sMsg) 0BTLcEqgZ
{ <_:zI r,
System.err.println(sMsg); kRot7-7I|
} +d39f-[
E $6ejGw-
1dv=xe.
public static void log(int sMsg) ')o0O9/;
{ xP@/9SM
System.err.println(sMsg); r nBOj#N
} }uQ${]&D
} Do;#NLrWb
yJD>ny
y1,5$0@G
/* |:2c$zq
**TestMethod.java mm,lhIh
*/ ULl_\5s2
package NetFox; y1C/v:;
lbkLyp2
#T%zfcUj
public class TestMethod { _413\`%8?
xzk}[3P{
l3J$md|f
public TestMethod() oI@9}*
{ ///xx/weblogic60b2_win.exe nem@sB;v#
try{ PDC]wZd/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {;k_!v{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K`4GU[ul
SiteFileFetch fileFetch = new SiteFileFetch(bean); V0NVGRQ
fileFetch.start(); sh6(z?KP
} %#k,6;m
catch(Exception e){e.printStackTrace ();} gaeOgP.0
=kFuJ x)f
`-O=>U5nH
} _4R,Ej}
yNva1I
og-]tEWA1
public static void main(String[] args) sv=H~wce
{ K^H>~`C=
new TestMethod(); Z[} $n-V
} "$8w.C
} &;v!oe
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