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)); Z,F1n/7
} r&XxF>
for(int i=0;i<nEndPos.length-1;i++) zaE!=-U
{ *mN8Qd
nEndPos = nStartPos[i+1]; ;47=x1ji
} TQ5kT?/{
nEndPos[nEndPos.length-1] = nFileLength; 5%DHF-W)
} Q%t _Epe
} wJ7Fnj>u%
vLCm,Bb2L
4_4|2L3
//启动子线程 G2J4N2hu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'RR,b*Ql
for(int i=0;i<nStartPos.length;i++) ?Y9VviC
{ B^x}=Z4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), };cH5bYF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w/7vXz<
nStartPos,nEndPos,i); h:vI:V[/X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qmnW
fileSplitterFetch.start(); "VAbUs
} UD5f+,_;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /{Z<!7u;U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }oii|=,#^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /6p7k
nEndPos = " + nFileLength); X!]p8Q y
// fileSplitterFetch[nPos.length-1].start(); ybgw#jv=
m pM,&7}
NW?h~2
//等待子线程结束 XN'<H(G
//int count = 0; cX48?srG
//是否结束while循环 U9q6m3#$
boolean breakWhile = false; Za1VJ5-
-O[9{`i]
W; ?'
while(!bStop) kL%o9=R1
{ w Yr M2X@
write_nPos(); |B@\Nf7
Utility.sleep(500); +/8KN
breakWhile = true; Yo2n[
~g;lVj,N'
0S>U_#-
for(int i=0;i<nStartPos.length;i++) XO4rrAYvW
{ u[coWaPsZ
if(!fileSplitterFetch.bDownOver) ldWr-
{ .^uYr^(|[
breakWhile = false; xA"7a
break; ^g n7DiIPH
} u_ym=N57`
} -r6LndQs
if(breakWhile) gz"I=9
break; #pp6 ycy
4B@L<Rl{\
},tn
//count++; [Ma d~;
//if(count>4) \-)augq([
// siteStop(); [+4--#&{
} &V7{J9
%!Ak]|[7
P 4jg]g
System.err.println("文件下载结束！"); uVV;"LVK~
} ]_P!+5]<
catch(Exception e){e.printStackTrace ();} 8w4cqr4m
} WiclG8l
8{J{)gF
ai(J%"D"
//获得文件长度 _#6ekl|%
public long getFileSize() x-ShY&k
{ s4Z5t$0|
int nFileLength = -1; `$N AK
try{ L\H,cimN
URL url = new URL(siteInfoBean.getSSiteURL()); +;wu_CQu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /YH5s=
httpConnection.setRequestProperty("User-Agent","NetFox"); ih/MW_t=m=
=lqGt.x
j`kw2(
int responseCode=httpConnection.getResponseCode(); L;k9}HWpP
if(responseCode>=400) 06S-3bis
{ `SO"F,
processErrorCode(responseCode); 4F>?G{ci
return -2; //-2 represent access is error <eG8xC
} *%xmCPJ
sDvtk]4o-4
4V0j1k&'
String sHeader; Z2u5n`K
w6[uM%fHG
#97w6,P+
for(int i=1;;i++) f_GqJ7Gk]
{ N_"mC^Vx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H{3A6fb<
//Utility.log(in.readLine()); :If1zB)
sHeader=httpConnection.getHeaderFieldKey(i); 7ehs+GI
if(sHeader!=null) F82_#|kpS
{ Jd>"g9
if(sHeader.equals("Content-Length")) 6?v)Hb}J%d
{ s'|^6/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3mnq=.<(w
break; ?1u2P$d
} (lY<\l
} Ju"*>66
else #(G#O1+
break; DpaPRA)x
} 4^mpQ.]lO
} p%v+\T2r
catch(IOException e){e.printStackTrace ();} RvT>{G~
catch(Exception e){e.printStackTrace ();} sOBy)vq?\
wLf=a^c#
GCTf/V\#
Utility.log(nFileLength); 3G7Qo
OK}+:Y
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return nFileLength; ,U#$Qb 12
} w1+xlM,,9
lJloa'%v9
iCYo?>
//保存下载信息（文件指针位置） ^Pk-<b4}
private void write_nPos() tOK lCc
{ {$ghf"
try{ >}~Pu| _S
output = new DataOutputStream(new FileOutputStream(tmpFile)); b4$-?f?V
output.writeInt(nStartPos.length); {b^JH2,
for(int i=0;i<nStartPos.length;i++) D d$ SQ
{ cDS6RO?
// output.writeLong(nPos); )J"Lne*"
output.writeLong(fileSplitterFetch.nStartPos); v~N8H+!d
output.writeLong(fileSplitterFetch.nEndPos); ):lq}6J#
} (&U8NeWZ
output.close(); {Y! -]_5
} k]=Yi;
catch(IOException e){e.printStackTrace ();} $6a55~h|(
catch(Exception e){e.printStackTrace ();} =sk]/64h``
} }.x&}FqXE
OJUH".o
H *gF>1
//读取保存的下载信息（文件指针位置） 7Xu.z9y
private void read_nPos() )r#^{{6[v
{ r1= :B'z
try{ ]$'w8<D>t,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1}{bHj
int nCount = input.readInt(); ^y,%Tv>
nStartPos = new long[nCount]; i-'rS/R
nEndPos = new long[nCount]; `)[bu
for(int i=0;i<nStartPos.length;i++) tU02t#8
{ Wv]NFHe#
nStartPos = input.readLong(); IG1+_-H:
nEndPos = input.readLong(); !`yg bI.
} 3rEBG0cf]
input.close(); ugtb`d{ Sl
} u~,@Zg87
catch(IOException e){e.printStackTrace ();} 5__8+R
catch(Exception e){e.printStackTrace ();} <B*}W2\
} %{*}KsS`p
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9WaKsdf
private void processErrorCode(int nErrorCode) |5 sI=?p&t
{ (#WE9~Sru
System.err.println("Error Code : " + nErrorCode); 1)8;9 Ba:
} 6Hz45
gQJy"f
XAV|xlfm
//停止文件下载 $:R"IqDG
public void siteStop() \Ze"Hv
{ `Tx1?]
bStop = true; :bxq%D%|o
for(int i=0;i<nStartPos.length;i++) LY%`O#i.
fileSplitterFetch.splitterStop(); `gIlS^Q
M~Yho".
o:<gJzg
} ,[rh7_
} `CP}1W>
//负责部分文件的抓取 z}vgp\cuT
**FileSplitterFetch.java CY&Z*JI"'B
*/ P%8zxU;
package NetFox; %,-oxeM1u
^w eU\
3[: |)i)
import java.io.*; iEG`+h'
import java.net.*; fdIk{o
A`|OPi)
8'Eu6H&$G
public class FileSplitterFetch extends Thread { ZW$PJmz
rAK}rNxI
L`%v#R
String sURL; //File URL )]"aa_20]
long nStartPos; //File Snippet Start Position Zs _Jn
long nEndPos; //File Snippet End Position I^pD=1Y]
int nThreadID; //Thread's ID /jdq7CF
boolean bDownOver = false; //Downing is over B1]dub9
boolean bStop = false; //Stop identical `Z*k M VN
FileAccessI fileAccessI = null; //File Access interface hfpSxL
D}1Z TX_
!JtVp&?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x?0ZzB),
{ H]5%"(h
this.sURL = sURL; >}`q4U6$
this.nStartPos = nStart; 9S ~!!7oj
this.nEndPos = nEnd; )x1LOMe
nThreadID = id; ln#Jb&u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DGMvYNKTj
} %UuV^C
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d Ybb>rlu
public void run() ^lCys
{ ?Xscc mN
while(nStartPos < nEndPos && !bStop) #!d@;=[\
{ <(rf+Ou>I
-I7"9}j3
-,NiSh}A
try{ 1s4+a^&
URL url = new URL(sURL); +;7Rz_.6f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4-@D`,3L
httpConnection.setRequestProperty("User-Agent","NetFox"); Z `FqC
String sProperty = "bytes="+nStartPos+"-"; m&xyw9a
httpConnection.setRequestProperty("RANGE",sProperty); Ti`H?9t
Utility.log(sProperty); ` V}e$
[,s{/OM
Gma)8X#
InputStream input = httpConnection.getInputStream(); md_9bq/w
//logResponseHead(httpConnection); x35(i
=vxiqRm
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byte[] b = new byte[1024]; }Wf\\
int nRead; 1{B^RR.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fj<#*2{]B
{ "G\OKt'Z
nStartPos += fileAccessI.write(b,0,nRead); |7Z7_YWs
//if(nThreadID == 1) ?[>+'6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CN6@g^)P
} M#II,z>q
2fp\s5%J}
L M
Utility.log("Thread " + nThreadID + " is over!"); tmF->~|
bDownOver = true; Mq!03q6
//nPos = fileAccessI.write (b,0,nRead); A+d&aE}3V
} _ F&BSu
catch(Exception e){e.printStackTrace ();} f6x}M9xS%
} ]J\tosTi
} (Hqy^EOZ
V3&_ST
_idTsd:\
//打印回应的头信息 fMaUIJ:Q9
public void logResponseHead(HttpURLConnection con) ]YcM45xg
{ Ie(vTP1Cj
for(int i=1;;i++) VmM?KlC
{ #8P9}WTno.
String header=con.getHeaderFieldKey(i); d4h1#MK
if(header!=null) n gA&PU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); swv1>52{
Utility.log(header+" : "+con.getHeaderField(header)); M&Aeh8>uX
else $i&u\iL
break; "*O(3L.c-
} epa)~/sA
} .K>rao'
6XPf0Gl
..RCR_DIp
public void splitterStop() 1Wzm51RU
{ .JIn(
bStop = true; XPnN"Y"y
} ,B]kX/W
y'ULhDgq^B
O(BAw
} u!TVvc
L=W8Q8hf
[5$=G@ zf
/* Q C?*O?~#
**FileAccess.java dLQV>oF
*//文件访问(定位，写) L1;IXCc=
package NetFox; >D'Kt?L<]m
import java.io.*; o.-rdP0P>
ydFZ$W_}w
N<V,5
public class FileAccessI implements Serializable{ s,UccA@
cTf/B=yMi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6|*em4
RandomAccessFile oSavedFile; J0@ ^h
long nPos; yZJR7+
wmh[yYWc
:|i jCg+
public FileAccessI() throws IOException umV5Y`
{ S EdNH.|I
this("",0); 7XLz Ewa
} 6@_Vg~=S
g:bw;6^u
^M60#gJ
public FileAccessI(String sName,long nPos) throws IOException H2oAek(
{ |pB[g>~V
oSavedFile = new RandomAccessFile(sName,"rw"); )r_zM~jI
this.nPos = nPos; p:]kH
oSavedFile.seek(nPos); "]|I;I"b
} 6X{RcX]/
.s7Cr0^k,|
ghq#-N/t
public synchronized int write(byte[] b,int nStart,int nLen) s UX%{|T_
{ pq0F!XmU
int n = -1; *gHGi(U(U
try{ =sVB.P
oSavedFile.write(b,nStart,nLen); F6 ?4E"d
n = nLen; ,#Y>nP0
} 595P04
catch(IOException e) 'LY.7cW
{ ^b-o
e.printStackTrace (); -DgJkyt+<
} gGl}~
}Xv2I$J
@?,iy?BSG
return n; `8$gaA*
} Z~O1$,Z
Aa^%_5
i^LLKx7M&
} kI5`[\
&_cMbFLBP
\ UCOe
/* !9+xKr99
**SiteInfoBean.java '5j$wr zt
*/ QAiont ,!
package NetFox; -A}U^-'a}
5AV5`<r.
P~Cx#`#(V
public class SiteInfoBean { AN;SRl
.H,v7L,~88
uzA"+cV5
private String sSiteURL; //Site's URL U2 0@B`<
private String sFilePath; //Saved File's Path I@x^`^+l
private String sFileName; //Saved File's Name l_ /q/8-l
private int nSplitter; //Count of Splited Downloading File fz H$`X'M
S+LE ASOr
1^<R2x
public SiteInfoBean() We]mm3M3
{//nSplitter的缺省值为5 NijvFT$V1
//default value of nSplitter is 5 8.9TWsZ
this("","","",5); A1`y_ Aj
} =<nx[J
7VWq8FH`
5c*kgj:x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kts#e:k@
{ |7G+O+j
sSiteURL= sURL; +AVYypql8K
sFilePath = sPath; A1{ 7g<k6
sFileName = sName; \bJ,8J1C
this.nSplitter = nSpiltter; ^,`;x
tz{W69k+
Lyjt$i W%
} /(#;(]
gWcl@|I;\
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public String getSSiteURL() ^_dYE]t
{ d;GF<bz
return sSiteURL; iY @MnnX
} nqX)+{wAXe
nSWW^ ;
&6*X&]V!Z
public void setSSiteURL(String value) M~ =Bln5
{ pa1.+~)
sSiteURL = value; ZMs$C3
} $2l<X KT-
iQryX(z
hrsMAh!
public String getSFilePath() SM3Q29XIw
{ {<f_,Nlc
return sFilePath; S%ULGX:@ga
} ESdjDg$[u
.GG6wL<$?
)m .KV5K!
public void setSFilePath(String value) Rlvb@aXgy
{ }:NE
sFilePath = value; 2, bo
} :CH?,x^!@
!?t#QDo
dW hU o\>=
public String getSFileName() >l|ao&z>bm
{ ".Lwq_
return sFileName; F/BB]gUB
} 7g'jg7
G&i<&.i
~";GH20
public void setSFileName(String value) m0XdIC]s
{ cuenDw=eC
sFileName = value; k+8K[?K-
} 6.X| .N
q/I':a[1
3C8cvi[IS
public int getNSplitter() JO*}\Es
{ ,Jqi J?,4C
return nSplitter; <5oG[1j
} ;|(_;d
[l;9](\8O
>z&|<H%
public void setNSplitter(int nCount) ,^]yU?eU
{ >fCz,.L
nSplitter = nCount; kNW}0CDgs
} U Ke!zI
} 3yT7;~vPj
tPDd~fOk
_T,X z_
/* udCum4
**Utility.java P.G`ED|K!Y
*/ ,Mt/*^|
package NetFox; ~zEBJgeyh
x8L$T(^
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public class Utility { }bwH(OOS
Bismd21F6=
e;QPn(
public Utility() {<\[gm\X
{ -)S(eqq1
g=8}G$su{%
)?@X{AN&
} E038p]M!
!3]}3jZ.
//线程睡眠 !3Xu#^Xxj
public static void sleep(int nSecond) AQCU\E
{ &~ =q1?
try{ 8T3j/D<r
Thread.sleep(nSecond); 3vs;ZBM
} zq(R!a6
catch(Exception e) .W>LsEk
{ Dwvd
e.printStackTrace (); pq<302uBQ
} 3v oas
} y _Mte
xp+Z%0D
//日志 (`z`ni
public static void log(String sMsg) . 4$SNzv3V
{ 5u(B]_r.
System.err.println(sMsg); Ni"M.O);t
} eVDO]5?
4d\1W?i-
:%&~/@B
public static void log(int sMsg) 'IR2H{Q
{ [QC|Kd^#
System.err.println(sMsg); %XIPPEHU
} ;QVX'?
} i,77F!
hrLPyV:
~,199K#'
/* U _QCe+
**TestMethod.java I/F3%'O
*/ dd$}FlT
package NetFox; Vn4y^_H
=!@5!
h]|E,!H
public class TestMethod { >P@JiR<@\n
^o`;C\
*b< a@
public TestMethod() v/\in'H~
{ ///xx/weblogic60b2_win.exe X-xN<S q
try{ JYE[ 1M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L.5 /wg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8SJi~gV
SiteFileFetch fileFetch = new SiteFileFetch(bean); j?5s/
fileFetch.start(); C(t>ZR
} }ioHSkCD
catch(Exception e){e.printStackTrace ();} hB]\vA7
znNJ?
*G]zN"Y
} I2U/\
"JHdF&
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public static void main(String[] args) ]z^*1^u^ig
{ {w,g~ew `
new TestMethod(); D7|=ev
} WH@CH4WM
} 9&FFp*'3
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