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)); I&4|T<j
} mp}ZHufG
for(int i=0;i<nEndPos.length-1;i++) E}~GXG
{ */6PkNq
nEndPos = nStartPos[i+1]; gzeG5p
} Ra.<D.
nEndPos[nEndPos.length-1] = nFileLength; <CeDIX t
} 90Q}9T\
} hEDj"`Px
'l2`05
9Czc$fSSt
//启动子线程 sI#K01;"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cBU>/ zIp
for(int i=0;i<nStartPos.length;i++) ucyxvhH^-
{ 0rF{"HM~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _Nw-|N.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /KH3v!G0
nStartPos,nEndPos,i); syMB~g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9kTU|py
fileSplitterFetch.start(); !}U&%2<69
} HuG|BjP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KN5.2pp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tf` ~=fg%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QH;1*
nEndPos = " + nFileLength); s<n5^Vxy
// fileSplitterFetch[nPos.length-1].start(); [5>0om5
dY|(
gwNv;g
//等待子线程结束 nXXyX[c4e
//int count = 0; Y*J,9
//是否结束while循环 ,myl9s
boolean breakWhile = false; \=1k29O
=Bl#CE)X
UDhW Y.`'~
while(!bStop) 5X'[{'i,
{ ?NJ\l5'
write_nPos(); &vo]l~.
Utility.sleep(500); R:-^,/1
breakWhile = true; 0Bb amU
AS~O*(po
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for(int i=0;i<nStartPos.length;i++) 4?;1cXXA
{ BoXQBcG]w
if(!fileSplitterFetch.bDownOver) I@e{>}
{ 5yuR[VU
breakWhile = false; nx84l7<
break; [26"?};"%
} S'lZ'H/
} YEQ}<\B\&
if(breakWhile) [ q22?kT
break; PO1sVP.S
8nW#Q<s
}3ty2D#/:
//count++; MX]<tR`
//if(count>4) % ?@PlQ
// siteStop(); "2$C_aE
} Z#%4QIz?
zN0^FXGD
X^7bOFWE
System.err.println("文件下载结束！"); zq8LQ4@ay
} U8;k6WT|
catch(Exception e){e.printStackTrace ();} C([TolZ
} >^{}Hjt
|s+y]3-_
C&D!TR!K
//获得文件长度 X*/jna"*
public long getFileSize() 9H`Q |7g(5
{ gM '_1zs U
int nFileLength = -1; ^F/N-!}q
try{ +<(N]w*
URL url = new URL(siteInfoBean.getSSiteURL()); PH^AT<U:T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !D!Q]M5oU
httpConnection.setRequestProperty("User-Agent","NetFox"); eE '\h
]`b/_LJN$F
M1-n
int responseCode=httpConnection.getResponseCode(); vg5i+ry<
if(responseCode>=400) @/g%l1$`
{ `,3;#.[D
processErrorCode(responseCode); H_un3x1
return -2; //-2 represent access is error qn5e[Vn
} KQ9~\No]
g/)mbL>=
fq48>"g*
String sHeader; <}&n}|!
IXDj;~GF
P{h;2b{
for(int i=1;;i++) Mpzt9*7R
{ qk<(iVUO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kFg@|#0v9
//Utility.log(in.readLine()); cQ} ,q+GR~
sHeader=httpConnection.getHeaderFieldKey(i); kl,I.2-
if(sHeader!=null) *VG#SK
{ olB?"M=H
if(sHeader.equals("Content-Length")) N7v7b<6
{ Tu"bbc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bH%k)
break; p8aGM-+40W
} ?%Hj,b
} qcSlqWDk
else )"`(+Ku&c
break; ph qx<N@
} <lopk('7
} P-o/ax
catch(IOException e){e.printStackTrace ();} }6*+>?
catch(Exception e){e.printStackTrace ();} o$)pJ#";F
7o_1PwKS6
G:7HL5u
Utility.log(nFileLength); ry)g<OA
>4 4A
_bRd2k,
return nFileLength; DO` K_B
} ?%-VSL>$w=
P MV;A{T
w\ 4;5.$
//保存下载信息（文件指针位置） "%ou'\}
private void write_nPos() <&^P1x<x
{ n;+CV~
try{ R9@Dd
output = new DataOutputStream(new FileOutputStream(tmpFile)); E%8Op{zv_
output.writeInt(nStartPos.length); v'na{"
for(int i=0;i<nStartPos.length;i++) GrPKJ~{6
{ ieo Naq
// output.writeLong(nPos); {RcmjI7
output.writeLong(fileSplitterFetch.nStartPos); o b;]
output.writeLong(fileSplitterFetch.nEndPos); X67^@~l
} 5#|D1A
output.close(); X$Eg(^La
} Mm7;'Zbg
catch(IOException e){e.printStackTrace ();} q#s:2#=
catch(Exception e){e.printStackTrace ();} q$RJ3{Sf
} 6Y9FU
&\6Buw_
&.^(,pt
//读取保存的下载信息（文件指针位置） 5ar2Y$bY
private void read_nPos() r*_z<^d
{ Bp&7:snGt
try{ IC"lsNq52
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r:;nv D
int nCount = input.readInt(); #@%DY*w]v
nStartPos = new long[nCount]; iXLODuI
nEndPos = new long[nCount]; a4{~.Mp
for(int i=0;i<nStartPos.length;i++) sT8(f=^)8F
{ J,q6
nStartPos = input.readLong(); Uao8#<CkvJ
nEndPos = input.readLong(); K ?uHAm
} jEU`ko_
input.close(); q9+`pj
} X%JQ_Z
catch(IOException e){e.printStackTrace ();} 3<F\5|
catch(Exception e){e.printStackTrace ();} .Z?@;2<l
} T<XGG_NOl
3mef;!q
8[v9|r
private void processErrorCode(int nErrorCode) ZW+M<G
{ {o>51fXc)
System.err.println("Error Code : " + nErrorCode); w8veh[%3n
} H#/ #yVw
q~:H>;:G-
zP554Gr?
//停止文件下载 im,H|u_f4
public void siteStop() n$Nb,/o
{ @}K|/
bStop = true; n0)0"S|y1
for(int i=0;i<nStartPos.length;i++) C?dQ QB$
fileSplitterFetch.splitterStop(); Odn`q=
[7Fx#o=da
r{LrQ
} }`fFzb
} ?`T0zpC
//负责部分文件的抓取 +|0f7RB+R
**FileSplitterFetch.java IkWV|E
*/ /6fa 7;
package NetFox; X%X`o%AqC
R;d)I^@
0+3_CS++r
import java.io.*; !V.2~V[^M
import java.net.*; =1ltX+
lKVV*RR}
G.{)#cR
public class FileSplitterFetch extends Thread { !m {d6C[
1Jm'9iy3
yj$a0Rgkv
String sURL; //File URL 2eC`^
long nStartPos; //File Snippet Start Position t@(:S6d
long nEndPos; //File Snippet End Position t_xO-fT)
int nThreadID; //Thread's ID b?^CnMO
boolean bDownOver = false; //Downing is over U~CG(9
boolean bStop = false; //Stop identical ]9A@iA
FileAccessI fileAccessI = null; //File Access interface SHow~wxw
xVnk]:c
)t#>fnN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]#NJ[IZb
{ "5wer5? t
this.sURL = sURL; npCiqO
this.nStartPos = nStart; ,vcg%~-
this.nEndPos = nEnd; Q$bi:EyJXc
nThreadID = id; 1`& Yg(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Sgp1p}
} tRZA`&
r'F)8%
/`kM0=MMa
public void run() {D{' \]+
{ 18eB\4NlD
while(nStartPos < nEndPos && !bStop) D`9a"o
{ (_0r'{`
V|\dnVQ'-%
ZbAg^2
try{ 5mqwNAv
URL url = new URL(sURL); w. c]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "L9yG:
httpConnection.setRequestProperty("User-Agent","NetFox"); [ !<
String sProperty = "bytes="+nStartPos+"-"; 0Z4o3r[
httpConnection.setRequestProperty("RANGE",sProperty); w;p~|!
Utility.log(sProperty); alp}p
P:OI]x4
k>.n[`>$6|
InputStream input = httpConnection.getInputStream(); $n#NUPzG+
//logResponseHead(httpConnection); ^]zC~LfG
Pd8zdzf{
Cs2F/M'
byte[] b = new byte[1024]; VN/v]
int nRead; huat,zLS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %G`GdG}T
{ k.n-JS
nStartPos += fileAccessI.write(b,0,nRead); }lQ`ka
//if(nThreadID == 1) 4\Q pS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~PZIYG"D
} AZH=r S`
'$0~PH&
S x0QPX
Utility.log("Thread " + nThreadID + " is over!"); 5H^"
bDownOver = true; ExxD w_VGT
//nPos = fileAccessI.write (b,0,nRead); Ri<'apl
} eEmuE H@X
catch(Exception e){e.printStackTrace ();} JwNB)e D
} TgjM@ir
} y#iQ
BM>'w,$KL
dWi:V7t+
//打印回应的头信息 [/Vi*Z
public void logResponseHead(HttpURLConnection con) &YOks.k
{ 1yd}F`{8UF
for(int i=1;;i++) "CTK%be{q/
{ MJ_]N+
String header=con.getHeaderFieldKey(i); )|N_Q}
if(header!=null) 5fvY#6;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iXPe
Utility.log(header+" : "+con.getHeaderField(header)); 0`Hr(J`F
else T$IwrTF@?
break; M"\j7(
} |r<#>~*
} +t7n6
?,z/+/:
_O;2.M%@
public void splitterStop() hdN[wC]
{ 231,v,X[
bStop = true; _%gu<Ys
} EQ%,IK/
[X^Oxs
ZW@%>_JR]
} z@Uf@~+U
iOrpr,@
HP(dhsd<c
/* [k{2)g
**FileAccess.java b^^ .$Gu
*//文件访问(定位，写) 3PUyua'
package NetFox; c]PG5f xf
import java.io.*; jnIf(a
O.z\ VI2f
dxi5p!^^9
public class FileAccessI implements Serializable{ )aAKxC7w
L_O*?aaZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0^9%E61YR
RandomAccessFile oSavedFile; ]9PQKC2&
long nPos; Me2qOc^Z-
VdOcKP.
; S~
public FileAccessI() throws IOException rWULv
{ U#6<80Ke
this("",0); x2h5,.K
} }8eu 9~
'Da*MGu9
w#^z:7fI
public FileAccessI(String sName,long nPos) throws IOException srQ]TYH ,
{ M37GQvo
oSavedFile = new RandomAccessFile(sName,"rw"); 73kU\ux
this.nPos = nPos; 0WI@BSHnM
oSavedFile.seek(nPos); 11YpC;[o
} L+D9ZE]
b <z)4
@/W~lJ!e
public synchronized int write(byte[] b,int nStart,int nLen) >m+Fm=
{ Z/G?wD|B
int n = -1; Wy.^1M/n>~
try{ @(W{_mw
oSavedFile.write(b,nStart,nLen); wCgi@\
n = nLen; Ohn?>qQ
} FH)_L1n
catch(IOException e) >K n7A
{ 5>\~jf
e.printStackTrace (); )>;V72
} 1n!xsesSc
SIZZFihcYh
Fk#$@^c@
return n; YR-Ge
} >/.w80<'
hxZL/_n'
0s!';g Q
} {1;R&
qO{Yr$V%
N4)ZPLV
/* <7 xX/Z}M
**SiteInfoBean.java "[dfb#0z`
*/ O9ar|8y
package NetFox; Yfr4<;%
b_Dd$NC
!2F X l;
public class SiteInfoBean { %R^*MUTx
.]YTS
7q(A&
private String sSiteURL; //Site's URL I=2b)"t0
private String sFilePath; //Saved File's Path $pJw p{kN
private String sFileName; //Saved File's Name #HTq\J!
private int nSplitter; //Count of Splited Downloading File YY4q99^K
YkSHJ{>
x@3" SiC
public SiteInfoBean() J%FF@.)k
{//nSplitter的缺省值为5 ;6M [d
//default value of nSplitter is 5 K$KVm^`
this("","","",5); lWakyCS
} {I8C&GS
|8?DQhd}
x|$|~6f=n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X/ lmj_v
{ tID=I0D
sSiteURL= sURL; SS6K7
sFilePath = sPath; 6aKfcvf &
sFileName = sName; nc^DFP
this.nSplitter = nSpiltter; +_1sFH`
Y?ZzFd,i&
NXX/JJ+w
} l5/gM[0_7
B \LmE+a>
SW}?y%~
public String getSSiteURL() mXs.@u/
{ IU;a$
return sSiteURL; G%ZP`
} UM<!bNz`
8j)*T9
8"}8Nrb0
public void setSSiteURL(String value) 8.:WMH`
{ GfV#^qi
sSiteURL = value; &grqRt
} a}Z+"D
H128T8?r[
b|-S;cw
public String getSFilePath() E>iN>
{ xqb*;TBh*
return sFilePath; ?I$-im
} ~REfr}0
[2PPa9F
HR;I}J 9
public void setSFilePath(String value) 1Qw_P('}
{ _#qfe
sFilePath = value; sC A
} =Z ql6D
szCB}WY
dNf:I,<DCf
public String getSFileName() Tje(hnN
{ -3u ;U,}
return sFileName; <eZ*LK?
} Iz[ohn!f
6{quO#!
&["e1ki
public void setSFileName(String value) d(yTz&u)
{ 6Yl+IP];i
sFileName = value; e%EO/ 2"
} @nAl*#M*D
c:[ZknnCe
'Y.6sB
public int getNSplitter() m(D+!I9
{ aS``fE;O
return nSplitter; |`xM45
} p-r[M5;-^Q
n,d)Wwe_`y
%lD+57=
public void setNSplitter(int nCount) O4Q"2
{ `?O0)
nSplitter = nCount; 7MGvw-Tpb7
} qtmKX
} 3YJ"[$w='(
w2 r
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/* [N12X7O3
**Utility.java MT7B'hd
*/ ~oJ"si
package NetFox; =^SxZ Bn
\2]_NU5.
\Hdsy="Dnh
public class Utility { tcO{CI
xP,b/T#a
X`1R&K;z^
public Utility() T2 S fBs
{ VFzIBgJ3
I]DD5l}\
g+5c"Yk+u~
} BNj_f
YRo,wsj
//线程睡眠 <#RVA{
public static void sleep(int nSecond) C$0g2X
{ R8_I ASs
try{ 'y=N_/+s
Thread.sleep(nSecond); #?V rt,n
} E7M_R/7@y
catch(Exception e) dOa9D
{ b\"w/'XX
e.printStackTrace (); D$7#&2y
} !sSq4K
} Mc<u?H
@Ns[qn;9
//日志 kY @(-
public static void log(String sMsg) R|v'+bv
{ *ziR&Fr!
System.err.println(sMsg); XbqMWQN*
} ]8}51y8
o<G#%9j
AYgXqmH~+
public static void log(int sMsg) DU0/if9.
{ .] sJl
System.err.println(sMsg); ^lAM /
} 8;V9%h`P>
} nYFrp)DLK
FY ms]bv
I#&r5Q
/* NC#F:M;b
**TestMethod.java s2#Ia>5!
*/ i'7+ ?YL
package NetFox; D:;idUO
LP=j/qf|
d 8DU[p
public class TestMethod { ](A2,F 9(U
T*f/M
>WIc"y.
public TestMethod() xbm%+
{ ///xx/weblogic60b2_win.exe ]S%(l,
try{ l6y}>]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W3:Fw6v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nuXL{tg6
SiteFileFetch fileFetch = new SiteFileFetch(bean); XzHR^^;u"*
fileFetch.start(); b:D92pH
} 8.[F3Tk=
catch(Exception e){e.printStackTrace ();} S0)JIrrHC
&CQO+Yr$l
Y.\x.Hg
} $[A\i<#
pYx,*kG:HW
D]]wJQU2
public static void main(String[] args) &cSVOsi
{ )63 $,y-;$
new TestMethod(); Z*ip=FYR
} 4P&2Z0
} 80Dn!9j*
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