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)); '7S!6kd?
} .E?bH V
for(int i=0;i<nEndPos.length-1;i++) lBizC5t!o
{ (=S"Kvb~#
nEndPos = nStartPos[i+1]; ^KaqvG$ed
} z v L>(R
nEndPos[nEndPos.length-1] = nFileLength; 12%z3/i
} h(+m<J
} ~`nm<
=;'ope(?S
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//启动子线程 &hSnB~hi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2)HxW}o
for(int i=0;i<nStartPos.length;i++) 1NE!=;VOl
{ q\\8b{~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tEpIyC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1kz9>;Ud6
nStartPos,nEndPos,i); #;qFPj- v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); doxdRYKL
fileSplitterFetch.start(); |o;j0
} glOqft&>`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X~IRpzC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [[/ }1%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wHBHkz
nEndPos = " + nFileLength); CrRQPgl+u
// fileSplitterFetch[nPos.length-1].start(); 60U{ e}Mkb
!0!P.Q8>&
mMD$X[:
//等待子线程结束 zR3lX}g
//int count = 0; PMz{8 F
//是否结束while循环 []6ShcqJ[v
boolean breakWhile = false; r?Zy-yQ
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`g4Ekp'Rp[
while(!bStop) pQ[o3p!&9
{ !_^{udB}
write_nPos(); !9e\O5PmO
Utility.sleep(500); '0])7jq
breakWhile = true; Q5`+eQ?_\
eCPKpVhP
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for(int i=0;i<nStartPos.length;i++) 34+)-\xt:
{ VrnK)za*H
if(!fileSplitterFetch.bDownOver) )$9C`d[
{ ecSdU>
breakWhile = false; .Y^d9.
break; .NNcc4+
} HiS,q0
} }e/[$!35
if(breakWhile) vJ'yz#tl9
break; 4cErk)F4
Yq)YS]
m&8U4uHN
//count++; [#,X$O>
//if(count>4) K8yyxJ
// siteStop(); +aXk^+~j
} l7D4`i<F
j"D0nG,
Mi%1+
System.err.println("文件下载结束！"); mhJOR'2
} k?|F0e_
catch(Exception e){e.printStackTrace ();} DS[l,x
} Chb4VoE
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Rrs`h `'-
//获得文件长度 +lDGr/
public long getFileSize() RB$ 8^#
{ 'wT./&Z
int nFileLength = -1; gR_b~^
try{ l;][Q]Z@V
URL url = new URL(siteInfoBean.getSSiteURL()); 2Xj-A\Oh~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v#<+n{B
httpConnection.setRequestProperty("User-Agent","NetFox"); *~t$k56
?:;hTY
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int responseCode=httpConnection.getResponseCode(); [r~rIb%Zj
if(responseCode>=400) ;t@ 3Go
{ vCU&yXGl
processErrorCode(responseCode); 1vR#FE?
return -2; //-2 represent access is error 5@%=LPV
} ^&G O4u
qdkTg:QJ,
)l!&i?h%
String sHeader; UNZVu~WnF
m?R+Z6c[
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for(int i=1;;i++) L+0N@`nRF
{ as!|8JE`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); in;+d~?
//Utility.log(in.readLine()); I+4qu|0lA
sHeader=httpConnection.getHeaderFieldKey(i); .*wjkirF#~
if(sHeader!=null) [F>n!`8
{ C7*Yg$`{
if(sHeader.equals("Content-Length")) 2QuypVC ]
{ bl=*3qB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dil4ut-$
break; {*]=qSz
} T?}=k{C]
} q&Ua(I
else GPhwq n{
break; qpEC!~y
} cJE>;a
} b!tZbX#
catch(IOException e){e.printStackTrace ();} u #QSa$P
catch(Exception e){e.printStackTrace ();} 1p5q}">z
`9"jHw`D
x?k |i}Q
Utility.log(nFileLength); '`A67bdq)
ne~#{q
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return nFileLength; oO9iB:w
} Z.Y8z#[xg
HBkQ`T
*q9$SDm
//保存下载信息（文件指针位置） [zt&8g
private void write_nPos() &(U=O?r7
{ KqIe8bi^G
try{ Fl(ZKpSZU
output = new DataOutputStream(new FileOutputStream(tmpFile)); hdDI%3vk3
output.writeInt(nStartPos.length); VQJ5$4a&
for(int i=0;i<nStartPos.length;i++) v?'k)B
{ sy#j+gZ
// output.writeLong(nPos); ;."{0gq
output.writeLong(fileSplitterFetch.nStartPos); Yy:sZJ
output.writeLong(fileSplitterFetch.nEndPos); k5\ zGsol
} "+"dALX{3K
output.close(); {y%O_-C'r
} W${sD|d-
catch(IOException e){e.printStackTrace ();} F,$$N>
catch(Exception e){e.printStackTrace ();} X~VZ61vNu
} 6E%k{ r
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yq^$H^_O p
//读取保存的下载信息（文件指针位置） Ho{?m^
private void read_nPos() Zl/+HU~
{ ?4dd|n
try{ ag4^y&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ApB'O;5
int nCount = input.readInt(); e"09b<69
nStartPos = new long[nCount]; (.t:sn"P
nEndPos = new long[nCount]; _E-GHj>k z
for(int i=0;i<nStartPos.length;i++) eh=bClk
{ BU .G~0
nStartPos = input.readLong(); @y%qQe/g
nEndPos = input.readLong(); a.ME{:a%
} 5{=MUU=
input.close(); C_&tOt
} 35\0g&
catch(IOException e){e.printStackTrace ();} N1+]3kt ~
catch(Exception e){e.printStackTrace ();} g9`ytWmM
} 5Ww\h
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Lg53 Ms%
private void processErrorCode(int nErrorCode) QpZhxp
{ D{}\7qe
System.err.println("Error Code : " + nErrorCode); cE#Y,-f
} }jXUd=.Nu
l0,O4k2'
nP /$uj
//停止文件下载 qd;f]ndo
public void siteStop() 'S ;vv]}Gs
{ N{@eV][Q
bStop = true; DA\O,^49h
for(int i=0;i<nStartPos.length;i++) 2^+"GCo
fileSplitterFetch.splitterStop(); >l[N]CQ
rGO3
kE|#mI[>
} ot6Pq}
} J)+eEmrU
//负责部分文件的抓取 +d15a%^`
**FileSplitterFetch.java !pXz-hxKT
*/ b s*Z{R
package NetFox; a+Nd%hoe
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]+S QS^4
import java.io.*; )FCqYCfk
import java.net.*; n(MEG'9}
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[J#(k`@
public class FileSplitterFetch extends Thread { F3'G9Xf8Q=
&c!-C_L 2
1jb@nxRjO
String sURL; //File URL )<&QcO_
long nStartPos; //File Snippet Start Position woKdI)f$
long nEndPos; //File Snippet End Position C,rZ}-
int nThreadID; //Thread's ID t$2{U
boolean bDownOver = false; //Downing is over z@j&vW
boolean bStop = false; //Stop identical Ky|0IKE8Z
FileAccessI fileAccessI = null; //File Access interface BcWReyO<M
];YOP%2
ZG|T-r;~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !{LwX Kf
{ k[m-"I%ZFX
this.sURL = sURL; S7*:eo
this.nStartPos = nStart; )*B.y|b#
this.nEndPos = nEnd; 6]*qx5m`<l
nThreadID = id; fQh!1R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I`l<}M
} .#}R$}e+
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public void run() 8?!Vr1x
{ N 2\,6<
while(nStartPos < nEndPos && !bStop) Qpc>5p![3
{ XR(kR{yo
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BN0))p
try{ i&#c+iTH
URL url = new URL(sURL); Rh|&{Tf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bb6_['y
httpConnection.setRequestProperty("User-Agent","NetFox"); =:DNb(
String sProperty = "bytes="+nStartPos+"-"; qdhD6#r
httpConnection.setRequestProperty("RANGE",sProperty); a,.9eHf
Utility.log(sProperty); 3-0Y<++W3>
vnE,}(M
3mWN?fC
InputStream input = httpConnection.getInputStream(); *hba>LZ
//logResponseHead(httpConnection); sE% n=Ww
_kfApO)O
q%l<Hw6{z
byte[] b = new byte[1024]; b1+Nm
int nRead; />$kDe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q-H]Hxv
{ G|V ^C_:
nStartPos += fileAccessI.write(b,0,nRead); e>/PW&Z8Z
//if(nThreadID == 1) wp$=lU{B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G7u85cie
} h4U .wk
hM-qC|!
v?}/WKe+0
Utility.log("Thread " + nThreadID + " is over!"); z 'j%.Dd8
bDownOver = true; xZhh%~
//nPos = fileAccessI.write (b,0,nRead); V'8 (}(s/
} %H54^Z<y
catch(Exception e){e.printStackTrace ();} `y4+OXZ^
} C M(g4fh
} 0W@C!mD~
!|SawT5t
HRk+2'wjAz
//打印回应的头信息 .d;/6HD[y
public void logResponseHead(HttpURLConnection con) kC)dia{$
{ (1ebE
for(int i=1;;i++) =6>mlI>i
{ *ood3M[M^
String header=con.getHeaderFieldKey(i); vg<_U&N=-r
if(header!=null) l ^{]pD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u VB&DE
Utility.log(header+" : "+con.getHeaderField(header)); |b|p0Z%7{
else Q-AN~k8+)[
break; 7kO 1d{u6b
} <I7UyCAF
} & )Z JT.S
P;h/)-q8
!9-dS=:Y
public void splitterStop() L_/.b%0)
{ Mb-C DPT
bStop = true; tUzuel*
} &_ber ad
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p[cC%3
} <~3@+EEM
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/* FJ/kumq
**FileAccess.java k(et b#
*//文件访问(定位，写) oo`mVRVf
package NetFox; $L(,q!DvH
import java.io.*; ${e{#
z`{x1*w_
g=b'T-
public class FileAccessI implements Serializable{ V;.=O}Lr
nlh%O@,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oA`Ncu5
RandomAccessFile oSavedFile; V_h, UYN
long nPos; .DHPKz`W0
s3oK[:/
IU&n!5d$)|
public FileAccessI() throws IOException .^uNzN~
{ GDhg VOW(
this("",0); L_Om<LO2
} wTqgH@rGtR
*&!&Y*Jzg
ONg_3vD{
public FileAccessI(String sName,long nPos) throws IOException TtlZum\
{ uPt({H
oSavedFile = new RandomAccessFile(sName,"rw"); j%0D:jOY]
this.nPos = nPos; 3(jI
oSavedFile.seek(nPos); :D;BA
} W A-\2
.*i.Z
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public synchronized int write(byte[] b,int nStart,int nLen) 5@6F8:x}V
{ \\xoOA.
int n = -1; V& _
try{ )$XcO]
oSavedFile.write(b,nStart,nLen); *7FtEk/l
n = nLen; a/^ojn
} G*JasHFs
catch(IOException e) ^,*!Qk<c
{ BRyrdt*_e
e.printStackTrace (); \$$DM"+:;H
} ) 7w%\i{M
!o1+#DL)MU
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return n; !E#FzY!}Pl
} nW1u;.
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RR |Z,
} C/_Z9LL?F
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wF[%+n (*
/* Qv~lH&jG
**SiteInfoBean.java e#BxlC
*/ EIug)S~
package NetFox; sYE|
Cj'XL}
zsOOx% +
public class SiteInfoBean { b*Sw")#
n%X5TJE
.Yg7V'R1
private String sSiteURL; //Site's URL WCRGqSr4
private String sFilePath; //Saved File's Path +`=rzL"0I7
private String sFileName; //Saved File's Name ~+ [T{{
private int nSplitter; //Count of Splited Downloading File 1L3+KD~
>sGIpER7
@|N{EI
public SiteInfoBean() |q!O~<H@
{//nSplitter的缺省值为5 QN)EPS:y
//default value of nSplitter is 5 Q!.JV.(
this("","","",5); ^Q,-4\ec
} V96:+r
[`(W(0U%
3'2>3Y/7Bb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `cgyiJ
{ sYa;vg4[
sSiteURL= sURL; <Ukeq0
sFilePath = sPath; Smg z}
sFileName = sName; s`#g<_{X
this.nSplitter = nSpiltter; jEu-CU#:
o&-D[|E|
<!;NJLe`
} r?7tI0
{?X:?M_
y8%QS*
public String getSSiteURL() tK7v&[cI
{ vLI'Z)\
return sSiteURL; tw k
} b=+3/-d
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public void setSSiteURL(String value) V10JExsJ
{ ;r?s7b/>
sSiteURL = value; wNvq['P
} Jo'~oZ$
(! a;}V<7
03Uj0.Z|7
public String getSFilePath() !(A<
{ '/2)I8
return sFilePath; ,eSII2,r4
} ,,8'29yEq
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public void setSFilePath(String value) 2=IZD `{!
{ s.$:.*k
sFilePath = value; 1$_|h@
} =C#22xqQ.
5Sz&j
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public String getSFileName() =I8^E\O("
{ _J&IL!S2
return sFileName; &0x;60b
} VV-%AS6;
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7<0oK|~c#
public void setSFileName(String value) y?'Z'
{ blx"WVqo
sFileName = value; F]GX;<`
} Ve\.7s
sq_ yu(
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public int getNSplitter() "N3!!3
{ X?7s
return nSplitter; Yij_'0vZ
} n,#o6ali>
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{VE1c'E"V?
public void setNSplitter(int nCount) +<Y1`kV)
{ T s9go
nSplitter = nCount; ZFC&&[%-sG
} @rE+H 5
} @yNCWa~N
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1VA%xOURh
/* m`&6[[)6~
**Utility.java RveEA/&&
*/ mXT{c=N)w
package NetFox; L"L a|
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public class Utility { ,a3M*}Y~3
]D_ AZI
=AP0{
public Utility() R-6km Tex>
{ QE6L_\l
J9&#);(
awgS5We|
} _iH:>2p5R
lm8<0*;,
//线程睡眠 ({<qs}H"
public static void sleep(int nSecond) , }B{)
{ YeI|&FMX
try{ .2 }5Dc,eR
Thread.sleep(nSecond); ? @- t.N
} ]Wn=Oc{F
catch(Exception e) GrA}T`]
{ #]2,1dJ
e.printStackTrace (); RY}:&vWDk
} obK6GG?ZE
} 4oPr|OKj{*
P\3H<?@4
//日志 Nazr4QU
public static void log(String sMsg) ]t-B-(D
{ 72\o6{BiC
System.err.println(sMsg); 42Cc`a%U
} ~}Z'/zCZf
r12e26_Ab
2{01i)2y
public static void log(int sMsg) ;HmQRiCg
{ ^.>XDUO F
System.err.println(sMsg); S[y?>
} T#3`&[
} `;Xwv)
K 5AArI
Ym wb2]M
/* "b0!h6$!H
**TestMethod.java g7r0U6Y
*/ b`^mpB*6R
package NetFox; ?Lem|zo
2+C8w%F8
9=G dj!L
public class TestMethod { hQLh}}B
S %(R9N|
<xAlp;8m5
public TestMethod() wb6$R};?
{ ///xx/weblogic60b2_win.exe e:(~=9}Li
try{ U/:x<Y$ tj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eQsoZQA1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }J] P`v
SiteFileFetch fileFetch = new SiteFileFetch(bean); XaYgl&x'!x
fileFetch.start(); i; 3qMBVY~
} fVxRK\a\\
catch(Exception e){e.printStackTrace ();} qD>D
=ve, !
Nu6]R677Y
} UY&DXIPM
(=w ff5U
V2*m/JyeB
public static void main(String[] args) 5YgUk[J
{ 0u8(*?
new TestMethod(); 5U.,iQ(d
} )q'~<QxI\
} uH8`ipX
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