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)); GWLdz0`2_
} =~5N/!
for(int i=0;i<nEndPos.length-1;i++) 5H1N]v+
{ \01kK)
nEndPos = nStartPos[i+1]; ?Qx4Z3n
} 'Va<GHr>+
nEndPos[nEndPos.length-1] = nFileLength; t+K1ArQc
} _Tm]tlV
} UA(4mbz+
@v3)N[|d
3D^cPkX
//启动子线程 qHT73_R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }=Xlac_U
for(int i=0;i<nStartPos.length;i++) )5n:UD{f[#
{ Q @[gj:w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O<#8R\v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p5% %k-
nStartPos,nEndPos,i); I1rB,%p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;&'ryYrex
fileSplitterFetch.start(); .FV^hrJxI;
} 4LW~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9hssIZO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KuW>^mF(I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )FPn_p#3]
nEndPos = " + nFileLength); 3hxV`rb
// fileSplitterFetch[nPos.length-1].start(); 6}VFob#h8
e=aU9v L
9Ofls9]U
//等待子线程结束 aqWlX0+
//int count = 0; Djdd|Z+*{
//是否结束while循环 v??$z#1F3
boolean breakWhile = false; Q*M(d\Vs
f:y1eLl3
M2c7|
while(!bStop) zR<fz
{ 9gglyoZ%
write_nPos(); O;i0xWUh
Utility.sleep(500); W\j)Vg__e
breakWhile = true; TD%L`Gk
B?yjU[/R
l}r9kS
for(int i=0;i<nStartPos.length;i++) hg#O_4D
{ 0S9~db
if(!fileSplitterFetch.bDownOver) fFYoZ/\
{ 7\[fjCg\w
breakWhile = false; 3o0ZS^#eB
break; xRdx` YYu
} y. 1F@w|
} 2i;ox*SfpU
if(breakWhile) cD=IFOB*GD
break; QleVW
z@w}+fYO
>]&Ow9-
//count++; u~2]$ /U
//if(count>4) :Ocw+X3
// siteStop(); +S[3HX7H
} Z[ &d2'
13w(Tf
4T;<`{]
System.err.println("文件下载结束！"); $d!Vxm
} H5&._
catch(Exception e){e.printStackTrace ();} bM5o-U#^ C
} (xoYYO
uubIL+
17,mqXX>
//获得文件长度 FvG?%IFM
public long getFileSize() aWH
{ ;E[Q/ tr:w
int nFileLength = -1; XogCq?_m
try{ v;U5[
URL url = new URL(siteInfoBean.getSSiteURL()); rGXUV`5Na
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %vm_v.Q4)
httpConnection.setRequestProperty("User-Agent","NetFox"); X,#~[%h$-=
(vX<Bh
vC`SD]
int responseCode=httpConnection.getResponseCode(); iRlpNsN
if(responseCode>=400) }ijQ*ECdl
{ IGT9}24
processErrorCode(responseCode); ,G5[?H;ZN
return -2; //-2 represent access is error mw}Bl; - O
} {:#nrD"
>iRkhA=Vg
,|}mo+rb-
String sHeader; V=% ;5/
9jX_Eoxy
>KvK'Mus/
for(int i=1;;i++) ^Y+Lf]zz*
{ b GI){0A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kP^A~ZO.
//Utility.log(in.readLine()); XPD1HN!,LT
sHeader=httpConnection.getHeaderFieldKey(i); ?w'86^_z
if(sHeader!=null) xy4+ [u
{ (Nk[ys}%*
if(sHeader.equals("Content-Length")) v3FdlE
{ 2<y9xvp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |#M|"7;2z
break; *8m['$oyV
} qk3|fW/-
} o kA<
else %D8.uGsh
break; I[v`)T'_{
} W]7/ e
} .-/IV^lGv
catch(IOException e){e.printStackTrace ();} c.b| RM0;
catch(Exception e){e.printStackTrace ();} **kix
YURMXbj
,7c Rd}1Y
Utility.log(nFileLength); .RJMtmp
X-kOp9/.
+egwZ$5I
return nFileLength; h~](9es
} Rz|@BxB>n
)RvX}y-
g#^MO]pY
//保存下载信息（文件指针位置） m8b,_1
private void write_nPos() !khEep}
{ 1' v!~*af
try{ 6h,!;`8O
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3NDddrL9
output.writeInt(nStartPos.length); Z+J4q9^$
for(int i=0;i<nStartPos.length;i++) `&7tADFB
{ -fmJkI
// output.writeLong(nPos); jVQ89vf ~
output.writeLong(fileSplitterFetch.nStartPos); RR ^7/-
output.writeLong(fileSplitterFetch.nEndPos); DyiJ4m}kh
} F]UH\1
output.close(); :S_]!'H
} 'ScvteQ
catch(IOException e){e.printStackTrace ();} L 1!V'Hm{
catch(Exception e){e.printStackTrace ();} )%MC*Z:^
} w:QO@
i2c|_B
)"6-7ii7(f
//读取保存的下载信息（文件指针位置） $HsNV6
private void read_nPos() QAp]cE1ew
{ 0]iaNR %
try{ n+hL/aQ+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \|HNFxT`
int nCount = input.readInt(); .6azUD4
nStartPos = new long[nCount]; "O<ETHd0
nEndPos = new long[nCount]; 2~?E'
for(int i=0;i<nStartPos.length;i++) PWiUW{7z
{ L*[3rqER
nStartPos = input.readLong(); Yg3nT:K_Y&
nEndPos = input.readLong(); W_JO~P
} 4fC:8\A
input.close(); ?SElJ?Z
} qJrKt=CE
catch(IOException e){e.printStackTrace ();} $=N?[h&4
catch(Exception e){e.printStackTrace ();} /B~[,ES@1
} ?X6}+
]4en|Aq
4,c6VCw3+
private void processErrorCode(int nErrorCode) Z%B6J>;uM
{ ybE2N
System.err.println("Error Code : " + nErrorCode); YnU)f@b#
} T!KwRxJ23
CCe>*tdf
|&rCXfC
//停止文件下载 ][v]Nk
public void siteStop() LrbD%2U$j5
{ -HQbvXAS
bStop = true; {DQ%fneN4
for(int i=0;i<nStartPos.length;i++) 8mKp PwG0
fileSplitterFetch.splitterStop(); %}VH5s9\
D4[t^G;J
z77>W}d
} }0Ns&6)xG
} aYb97}kI
//负责部分文件的抓取 ?V^7`3F
**FileSplitterFetch.java qz>R"pj0g
*/ /0XMQy
package NetFox; Tgr,1)T
()l3X.t,$
~BmA!BZV`
import java.io.*; ji1vLu4|t
import java.net.*; yW=+6@A4
C$1W+(
71{jedT
public class FileSplitterFetch extends Thread { A+0-pF2D
}QE*-GVv]
u/u(Z&
String sURL; //File URL 3^+D,)#D^
long nStartPos; //File Snippet Start Position U*$xR<8v
long nEndPos; //File Snippet End Position IUFc_uL@\
int nThreadID; //Thread's ID @nY]S\if
boolean bDownOver = false; //Downing is over F9u?+y-xb
boolean bStop = false; //Stop identical 5MAfuHq^
FileAccessI fileAccessI = null; //File Access interface ^F+7<$2
" L`)^
6D`n^uoP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =,#--1R7g
{ Ct w<-'
this.sURL = sURL; UgC65O2
this.nStartPos = nStart; \}?X5X>
this.nEndPos = nEnd; w&aZ 97{
nThreadID = id; 8'8`xu$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wc4BSJa,19
} ]2wxqglh)
]$[sfPKA
ujX;wGje
public void run() V^5d5Ao
{ k_=yb^6[U
while(nStartPos < nEndPos && !bStop) Ptv'.<-
{ T+F]hv'
Qw}1q!89
TB!I
try{ !B}9gT
URL url = new URL(sURL); 7t:RQ`$:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lz'VQO1U=
httpConnection.setRequestProperty("User-Agent","NetFox"); *7jz(iX
String sProperty = "bytes="+nStartPos+"-"; 0B]q /G(
httpConnection.setRequestProperty("RANGE",sProperty); +y?Ilkk;j
Utility.log(sProperty); Yg^ &4ZF
LZRg%3.E
v\Uk?V5T
InputStream input = httpConnection.getInputStream(); 4V')FGB$
//logResponseHead(httpConnection); Dp ](?Yr
rR> X<
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byte[] b = new byte[1024]; o[Jzx2A<
int nRead; (?na|yd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }|kFHodo
{ k||t<&`Ze
nStartPos += fileAccessI.write(b,0,nRead); -Lh7!d
//if(nThreadID == 1) 3N2dV6u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;/j2(O^
} qq| 5[I.?
ukW&\
"tzu.V-
Utility.log("Thread " + nThreadID + " is over!"); N7+L@CC6T
bDownOver = true; 6QX m]<
//nPos = fileAccessI.write (b,0,nRead); ixdsz\<
} 0Ds3wNz
catch(Exception e){e.printStackTrace ();} L=4+rshl!_
} !mmMAsd,
} }'$PYAf6
KhHFJo[8sf
lT^su'+bk
//打印回应的头信息 8s0+6{vW
public void logResponseHead(HttpURLConnection con) MEiP&=gX!
{ Xo34~V@(
for(int i=1;;i++) |`5IP8Z
{ ]dpL PR
String header=con.getHeaderFieldKey(i); vwU1}H
if(header!=null) >.iF,[.[F<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f~`=I NrU
Utility.log(header+" : "+con.getHeaderField(header)); Q5+1'mzAB
else 'dLw8&T+W
break; J?QS7#!%
} -b(DPte
} { qNPhi
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1UP=(8j/
public void splitterStop() tJ\ $%
{ a#YK1n[!
bStop = true; $F2Uv\7=
} dZU#lg
iVXt@[
lK0ny>RB
} [0 F~e
$.SBW=^V
\#{PV\x:Nn
/* *;Jb=
**FileAccess.java fjh|V9H
*//文件访问(定位，写) C$OVN$lL`8
package NetFox; 2%W;#oi?
import java.io.*; ,QY$:f<
+1ICX
m\L`$=eO8
public class FileAccessI implements Serializable{ b2m={q(s
Zse&{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j[G`p^ul
RandomAccessFile oSavedFile; }aZuCe_
long nPos; >HP `B2Q H
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u\]EG{w(
public FileAccessI() throws IOException !_S#8"
{ ~||0lj.D
this("",0); 6hxZ5&;(*
} kA:mB;:
v/+ <YU
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public FileAccessI(String sName,long nPos) throws IOException G;Li!H
{ Nd~B$venh
oSavedFile = new RandomAccessFile(sName,"rw"); s2;~FK#/
this.nPos = nPos; uoS:-v}/Y~
oSavedFile.seek(nPos); G{U#9
} IiU>VLa
XB)D".\
$|N6I
public synchronized int write(byte[] b,int nStart,int nLen) M.W X&;>
{ T ozx0??)
int n = -1; (bsx|8[
try{ |&; ^?M
oSavedFile.write(b,nStart,nLen); QL?_FwZL
n = nLen; z 6:Wh
} 0HzqU31%l@
catch(IOException e) AkhG~L
{ 77P\:xc
e.printStackTrace (); <J/ =$u/
} ma.84~m
i?x gV_q;
"tJ+v*E
return n; I|Oco?Q"
} }Q\%tZC#T
q~ H>rC(\
x/*lNG/
} oz)[-
"H-s_Y#
dljE.peL
/* c4Ebre-Oa
**SiteInfoBean.java <DF3!r
*/ qE[S>/R"
package NetFox; 3JnpI,By
l2D*b93
bJ~H
public class SiteInfoBean { DB'v7 Ij0
st-{xC#N#
8Q'Emw |
private String sSiteURL; //Site's URL 3SVGx<,2
private String sFilePath; //Saved File's Path l/.{F;3F
private String sFileName; //Saved File's Name EL 5+pt
private int nSplitter; //Count of Splited Downloading File J<$@X JLS
ARH~dN*C
akj<*,
public SiteInfoBean() a=z] tTs4
{//nSplitter的缺省值为5 M(%H
//default value of nSplitter is 5 e &6%
this("","","",5); TZn 15-O
} E/;t6&6
;tOsA #
^_2c\mw_I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H>~CL
{ |xO*!NR
sSiteURL= sURL; %yRXOt2(
sFilePath = sPath; "Xq_N4
sFileName = sName; Qb536RpcTY
this.nSplitter = nSpiltter; E&M(QX5
c;l!i-
XiUq#84Q
} MmF&jd-=
w#A)B<Y/"
[!'+}
public String getSSiteURL() 6Yu:v
{ &f*orM:
return sSiteURL; 1"h"(dA
} b8mH.g&l
q m3\)9C
b1&tk~D
public void setSSiteURL(String value) fvu{(Tb
{ ]Q^)9uE\D
sSiteURL = value; Cf% qap#
} 7=^{~5#
U3(+8}Q
=[B\50]
public String getSFilePath() I/E9:
{ 7^L
return sFilePath; ).~ "
} Kk3+ ]W<
p3s i\Fm!
f ULt4
public void setSFilePath(String value) <c+.%ka
{ 1`cH EAa
sFilePath = value; 2t= =<x
} Ge^`f<f
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)Z7Vm2a
public String getSFileName() X\^V{v^-
{ wJp<ZL
return sFileName; hnj\|6L
} u]p21)m$x
d:kB Zrq
?UnQ?F(+G<
public void setSFileName(String value) Jf YgZ\#
{ Kz HYh
sFileName = value; lC<;Q*Y
} 'zyw-1
}(EH5jZ'
e3I""D{)[=
public int getNSplitter() /jv/qk3i
{ 5.rAxdP
return nSplitter; $dC`keQM>9
} GppCrQ%Ra|
=LW!$p
N' hT
public void setNSplitter(int nCount) lY%I("2=
{ N>mW64_H)
nSplitter = nCount; 'uL4ezTtA
} (x=$b(I
} 7KC>?F
HuhQ|~C+~
\YP,}_~
/* b8WtNVd
**Utility.java cu!%aM,/<-
*/ jn(x-fj6R
package NetFox; c1YDln
"@Vyc6L
*22Vc2[i;
public class Utility { xyL"U*
Z.VKG1e}
tv#oEM9esl
public Utility() kK&w5'
{ WzIUHNn'I
IJ^~,+
'a#lBzu\b
} BP/nK.
p2vN=[g9)
//线程睡眠 J%"BCbxW~B
public static void sleep(int nSecond) 0|&@)`
{ @MSmg3&
try{ lQ8hY$
Thread.sleep(nSecond); g'.OzD
} br I;}m
catch(Exception e) rA~f68h|
{ Z?)g'n
e.printStackTrace (); 7;jD>wp9D
} "O34 E?ql.
} \|=6<ZY:
oe<i\uX8z
//日志 u\\t~<8
public static void log(String sMsg) Hw \of
{ (W}F\P
System.err.println(sMsg); WZQ2Mi<&1'
} c'oiW)8;A
$ XjijD9R
\n<! ld
public static void log(int sMsg) VLuHuih
{ erH,EE^-x<
System.err.println(sMsg); bRAD_
} 4'QX1p
} uw;Sfx,s
VF`!ks
fyQOF ItM
/* (b25g!
**TestMethod.java {&5lZ<nu8A
*/ m8sd2&4
package NetFox; .}==p&(
f-%M~:
QjTSbHtH
public class TestMethod { /U;j-m&
]az(w&vqg2
IkCuw./
public TestMethod() "6B@V=d
{ ///xx/weblogic60b2_win.exe T^v763%
try{ .a4,Lr#q.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o[Ffa#sE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |A&;m}(Mt
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8$IKQNS
fileFetch.start(); H/o_?qK
} K43%9=sM
catch(Exception e){e.printStackTrace ();} $DHE%IN`
q5;dQ8Y?
VZ9 p "
} N/tcW
E)-;sFz
7zu\tCWb
public static void main(String[] args) ]8A*uyi
{ | 0
new TestMethod(); X4%uY
} ]?6wU-a
} 8iIp[9~=
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