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)); e8z?) 4T
} <DEu]-'>
for(int i=0;i<nEndPos.length-1;i++) $bZ5@)E
{ *I k/Vu%;
nEndPos = nStartPos[i+1]; |"eC0u
} :G5O_T$
nEndPos[nEndPos.length-1] = nFileLength; 5mm&l+N)
} A3.pz6iT>
} 1h{7dLA
5/HkhTyj
(/i|3P
//启动子线程 RgzzbW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e :@PI(P!
for(int i=0;i<nStartPos.length;i++) YH{n
{ ?rdWhF]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R~RE21kAc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), shVEAT'`
nStartPos,nEndPos,i); |HwEwL+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7DeBeY
fileSplitterFetch.start(); # `@jVX0
} w@a|_?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ')(U<5y)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); acj-*I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3u,B<
nEndPos = " + nFileLength); M L7vP
// fileSplitterFetch[nPos.length-1].start(); +\>op,_9I
Q>L.
@q{.shqo
//等待子线程结束 nu[["f~
//int count = 0; g5*?2D}dqX
//是否结束while循环 /?}2OCq
boolean breakWhile = false; /9?yw!
0XA0b1VX
yFTN/MFt
while(!bStop) ]Z*B17//
{ <s'0<e!./t
write_nPos(); 65rf=*kz:
Utility.sleep(500); Mh@n>+IR
breakWhile = true; LeNSjxB
m'uFj !
"@Qg]#]JH
for(int i=0;i<nStartPos.length;i++) !=6\70lJ
{ v:NQrN
if(!fileSplitterFetch.bDownOver) g)IW9q2
{ UM^~a$t
breakWhile = false; #E_<}o
break; #+|0o-
} qga?-oz,<6
} R|_._Btu!
if(breakWhile) r,P`$-
break; NT9|``^Z
*thm)Mn
J.c yb
//count++; @Z<Z//^k
//if(count>4) XS.*CB_m_
// siteStop(); vr_Z0]4`C9
} bP4}a!t+n
4"\%/kG
WzBr1 ea{I
System.err.println("文件下载结束！"); D4~]:@v~n
} nL[G@1nR
catch(Exception e){e.printStackTrace ();} S[N9/2
} ff00s+
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`dRqheX
//获得文件长度 4Ofkagg
public long getFileSize() XcL%0%`
{ mo&9=TaG
int nFileLength = -1; `^h:}V
try{ q*cEosi'F?
URL url = new URL(siteInfoBean.getSSiteURL()); {*K$gH$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0:B%,nUM
httpConnection.setRequestProperty("User-Agent","NetFox"); Sar1NkD#
.=9d3uWJ/
Xx\,<8Xn
int responseCode=httpConnection.getResponseCode(); e-b>
if(responseCode>=400) GH`y-Ul'K
{ 4^:$|\?]
processErrorCode(responseCode); (ki= s+W-
return -2; //-2 represent access is error 0!tuUn
} rU1Ri
ACpecG
QuC_sFP10
String sHeader; _7dp(R
,,lR\!>8
"CZv5)
for(int i=1;;i++) M;YJpi
{ 32`Z3-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WADEDl&,'
//Utility.log(in.readLine()); js%n]$N
sHeader=httpConnection.getHeaderFieldKey(i); 0;hn;(V]"
if(sHeader!=null) UKPr[
{ ,RP9v*
if(sHeader.equals("Content-Length")) {@k , e
{ > }kZXeR|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [8K :ml
break; Sf@xP.d
} q4,/RZhzh
} dXsD%sG@
else OU!."r`9
break; -"?~By}<C
} l+X\>,
} d ,.=9
catch(IOException e){e.printStackTrace ();} ]EG8+K6
catch(Exception e){e.printStackTrace ();} A8Km8"
4vCUVo r
.}:*tvot
Utility.log(nFileLength); 4t>"-/
k$pND,Ws
Tr;.O?@{t}
return nFileLength; wc&D[M]-/
} 7NnXt'
z#GSt ZT
;<"V}, C
//保存下载信息（文件指针位置） 0Gu?;]GSv
private void write_nPos() k"%sdYkb!
{ >qmNT/
try{ DfVJ~,x~
output = new DataOutputStream(new FileOutputStream(tmpFile)); O- LwX >
output.writeInt(nStartPos.length); M}q;\}
for(int i=0;i<nStartPos.length;i++) Y/T-q<ag8
{ PWkSl
// output.writeLong(nPos); zS h9`F
output.writeLong(fileSplitterFetch.nStartPos); *zW]IQ'A
output.writeLong(fileSplitterFetch.nEndPos); -)R =p"-w
} 9<3fH J?vq
output.close(); #zBqj;p
} !!w(`kmn1
catch(IOException e){e.printStackTrace ();} $\bVu2&I
catch(Exception e){e.printStackTrace ();} VN'\c3;
} S(CVkCP
'fCSP|
LXPO@2QF
//读取保存的下载信息（文件指针位置） 2A9crL$
private void read_nPos() C%CgWO`Xj
{ q?@*
try{ v>N*f~n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wu(^k25
int nCount = input.readInt(); _x^rHADp
nStartPos = new long[nCount]; 1}+b4"7]
nEndPos = new long[nCount]; n$9Xj@+
for(int i=0;i<nStartPos.length;i++) L 4Z+8*
{ 7AWq3i{
nStartPos = input.readLong(); A}&YK,$5ED
nEndPos = input.readLong(); .rnT'""i<5
} rBy0hGx
input.close(); 62y:i
} xtKU;+#
catch(IOException e){e.printStackTrace ();} 6a_U[-a9;
catch(Exception e){e.printStackTrace ();} a'.7)f[g}
} \fuz`fK:
2)T;N`tNw
b?qV~Dgk`
private void processErrorCode(int nErrorCode) ]@#wR
{ o>bi~(H
System.err.println("Error Code : " + nErrorCode); q/d?cLgl
} yPs6_Qo!p
>Gk<a
po,Ue>n/
//停止文件下载 *ZFF$0}
public void siteStop() J9DI(`
{ {9.UeVz
bStop = true; 3IB9-wG
for(int i=0;i<nStartPos.length;i++) *X ;ch55\
fileSplitterFetch.splitterStop(); u0G tzk
`%"x'B`mM
&K(y%ieIJ
} /e*fsQ>M:
} #y[omla8
//负责部分文件的抓取 c h((u(G
**FileSplitterFetch.java 7Z<GlNv
*/ (n7{?`Yid
package NetFox; #g0N/
Fq5u%S
! Vlx
import java.io.*; I,HtW),
import java.net.*; e6 x#4YH
/e^) *r
B3u/ y
public class FileSplitterFetch extends Thread { ` aF8|tc_
|@yYM-;6
;Q4,I[?%
String sURL; //File URL aDxNAfP
long nStartPos; //File Snippet Start Position AXSip
long nEndPos; //File Snippet End Position YRr,{[e
int nThreadID; //Thread's ID 'mTY56Yq
boolean bDownOver = false; //Downing is over \ym^~ Q|
boolean bStop = false; //Stop identical MX7Ix{
FileAccessI fileAccessI = null; //File Access interface .Dl ?a>I
3EY m@oZj
=5V7212
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MI^$df
{ r<Cr)%z!
this.sURL = sURL; j(]O$""
this.nStartPos = nStart; `wU['{=
this.nEndPos = nEnd; 1#Hr{&2
nThreadID = id; !E_|Zp]up
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qSG0TWD!pq
} IYXN}M.=
yjH'<
0Q?%B6g$m[
public void run() jYFmL_{
{ t u{~:Z(
while(nStartPos < nEndPos && !bStop) ?!/8~'xA6
{ =Y6W Qf
'5[(QM5Gi&
47Bg[
try{ ,|>>z#Rr(n
URL url = new URL(sURL); SK^(7Ws~0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R8eBIJ/@_
httpConnection.setRequestProperty("User-Agent","NetFox"); Dq$1 j%4Y
String sProperty = "bytes="+nStartPos+"-"; ~gGkw#
httpConnection.setRequestProperty("RANGE",sProperty); }1~9i'o%Z
Utility.log(sProperty); #N>66!/V
"::2]3e
6NhGTLI
InputStream input = httpConnection.getInputStream(); %dq%+yw{%m
//logResponseHead(httpConnection); F kf4R5Y?
B)1(
K[0z$T\
byte[] b = new byte[1024]; D15-pz|Q
int nRead; u a_w5o7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g\@.qKF
{ S.1>bs2
nStartPos += fileAccessI.write(b,0,nRead); Ol+D"k~<C
//if(nThreadID == 1) ]?wz.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hfyU}`]
} !K}W.yv,
`BG>%#
qQG? k~r
Utility.log("Thread " + nThreadID + " is over!"); ~u2f`67{
bDownOver = true; n*na6rV\k
//nPos = fileAccessI.write (b,0,nRead); fDfph7[)
} a`#lYM%(>
catch(Exception e){e.printStackTrace ();} `XK\', }F
} l'wu-
} S7nx4c2xK~
~D4l64
Yk|.UuXT
//打印回应的头信息 m*N8!1Ot
public void logResponseHead(HttpURLConnection con) ~n%Lo3RiP
{ ) 5$?e
for(int i=1;;i++) ~+Pe=~a[
{ JJ}DYv
String header=con.getHeaderFieldKey(i); r hucBm
if(header!=null) Og1vD5a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $ B&ZnZ?
Utility.log(header+" : "+con.getHeaderField(header)); EA8plQ~GtE
else RtHai[j
break; "0#(<zb|
} >c<xy>N
} UdM2!f
./Ek+p*96H
Rk#'^}
public void splitterStop() y2s(]#8
{ j=M%*`@
bStop = true; BSgT 6K
} ?2Z`xL9QT
6Q]c}
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} tUc<ExvP,
M."/"hV`-
3x+=7Mg9
/* 2sk7E'2(
**FileAccess.java ``:[Jr&
*//文件访问(定位，写) NQ 6oyg@&
package NetFox; 1v`|mU}i,
import java.io.*; E7? n'!=
j<0;JAL
ux(~+<k
public class FileAccessI implements Serializable{ .nrbd#i-
la-:"gKC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *!&?Xy%\"j
RandomAccessFile oSavedFile; ,pGA|ob
long nPos; 4}/gV)
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#!UJY%c~
public FileAccessI() throws IOException q6C`hVMl
{ z7`|N`$Z#s
this("",0); -wV2 79^b
} ov,s]g83
h`N2M,
xi "3NF%=
public FileAccessI(String sName,long nPos) throws IOException z|%Pi J,
{ X5[t6q!
oSavedFile = new RandomAccessFile(sName,"rw"); {x,)OgK!{
this.nPos = nPos; 3Q=\W<Wu
oSavedFile.seek(nPos); np6G~0Y`
} 2v4K3O60G
} f&=}
Zf!Q4a"
public synchronized int write(byte[] b,int nStart,int nLen) ,;w~ VZ4
{ _&V,yp!|
int n = -1; FVrB#Hw~
try{ nf"#F@dk
oSavedFile.write(b,nStart,nLen); +<[q"3
n = nLen; tR'RB@kJ
} M`'DD-Q
catch(IOException e) 8Z9>h:c1
{ 'ZMh<M[
e.printStackTrace (); f7Nmvla[q
} ?i#x13
JXe~ 9/!
ly*v|(S&
return n; H(76sE
} ]zJO)(d$>
7UW\|r
U.t][#<3
} ]3Ia>i
!Ea!"}
<af# C2`B
/* ,v8e7T
**SiteInfoBean.java |w*s:p
*/ Fd<Ouyxqe
package NetFox; mL`8COA
,IboPh&Q78
|LQ%sV
public class SiteInfoBean { ]j/= x2p
1[Yl8W%pj
?|W3RK;
private String sSiteURL; //Site's URL Bt@?l]Y
private String sFilePath; //Saved File's Path zc)nDyn
private String sFileName; //Saved File's Name _p0Yhju?
private int nSplitter; //Count of Splited Downloading File Evm3Sm!S
[=jZP,b&),
ky[Cx!81C
public SiteInfoBean() EDgtn)1
{//nSplitter的缺省值为5 {*O+vtir%
//default value of nSplitter is 5 Bv@p9 ] n
this("","","",5); <H60rON
} _yN5sLLyb
$aJay]F
t>}S@T{~T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )$E){(Aa
{ [}HPV+j=U
sSiteURL= sURL; wQy~5+LE
sFilePath = sPath; ,%IP27bPW
sFileName = sName; dR\yRC]I
this.nSplitter = nSpiltter; T]&?^QGAZ
qF bj~ec
:3Q:pKg
} ` wEX;
o;Z"I&
1K@ieVc
public String getSSiteURL() \os"w "
{ 3<$Ek3X
return sSiteURL; )yig=nn
} @Drl5C}+
SQK82/
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public void setSSiteURL(String value) K(upzn*a
{ fG>3gS6&
sSiteURL = value; *Ts$Hj[
} "QXnE^
kK4a;j.#
>Df;1:U
public String getSFilePath() ]m 3cm
{ hIqUidJod
return sFilePath; N80ogio_Tk
} AA,/AKikd
ZJ2 MbV.6
jnJ*e-AW
public void setSFilePath(String value) (N&?Z]|yr
{ iKPgiL~
sFilePath = value; m\jjj^f a
} @uRJl$3
d5Ae67
Gy):hGgN
public String getSFileName() @,sjM]
{ ^ fC2o%3^
return sFileName; zKJQel5
} <CO_JWD
l59\Lo:
Z9M$*Zp
public void setSFileName(String value) )Hin{~h
{ rMIX{K)'f
sFileName = value; [UzacXt
} B6IKD
nm<VcCc
"A Bt
public int getNSplitter() FvVC 2Z
{ =Y|( }92
return nSplitter; C=&n1/
} NYHK>u/5c
PA ZjA0d
g4,ldr"D
public void setNSplitter(int nCount) 8=Oym~
{ n^{h@u
nSplitter = nCount; n5"oXpcIx
} J7",fb
} u4 es8"
1\@PrO35J
qZ[HILh!
/* fTR6]i;
**Utility.java 6:%lxG
*/ )ddJ\:
package NetFox; s/hWhaS<
l+2NA4s
P]^OSPRg
public class Utility { !Q~>)$Cf^
b6k_u9m^E
@R`6jS_gK
public Utility() ;Z0&sFm
{ O0'|\:my
O6?{@l
SN{A@dyt
} '/UT0{2;rS
UVlB=
//线程睡眠 ,h1\PT9ULY
public static void sleep(int nSecond) ~xY"P)(x;
{ zOSUYn
try{ 1QA/ !2E
Thread.sleep(nSecond); o>(<:^x9
} [N~7PNdS
catch(Exception e) #'KM$l,P
{ `qmwAT
e.printStackTrace (); 6 L4\UTr
} <?IDCOt ?
} %E@o8
c.LRS$o/j
//日志 /dg?6XT/
public static void log(String sMsg) Rkk`+0K7$J
{ j~\FDcG*ed
System.err.println(sMsg); H?;+C/-K`_
} dpS@:
]8}2
ws`r\k]3J
public static void log(int sMsg) x7E] }h
{ AKjobA#
System.err.println(sMsg); /f?;,CyI
} #FAW@6QG
} 6P>Y2xV:
(Q||5
ejR$N!LL
/* +-;v+{
**TestMethod.java 2"a%%fv
*/ l]&A5tz3
package NetFox; 3 $%#n*
w)S 4Xi=
Lct_6?
public class TestMethod { ec#`9w$
gh[q*%#
3O*iv{-&
public TestMethod() *>qc6d@'
{ ///xx/weblogic60b2_win.exe Z;~%!
try{ viU}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B=>Xr!pM!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r]xN&Ne5Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); N9d^;6;i
fileFetch.start(); [-l>fP0
} }03?eWk/y
catch(Exception e){e.printStackTrace ();} <!G /&T
sdCG}..`
V}<<?_
} :,p3&2I
3v3cK1K@oE
7^rT-f07
public static void main(String[] args) @eBo7#Zr
{ @6DKw;Q
new TestMethod(); |b='DJz2
} bt1bTo
} L=Aj+
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