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)); V'^s5
} .knRH^
for(int i=0;i<nEndPos.length-1;i++) lpve Yz
{ 2#6yO`?uo
nEndPos = nStartPos[i+1]; b)$<aFl
} E[2c`XFd8
nEndPos[nEndPos.length-1] = nFileLength; Y4!v1
} QS_"fsyN:
} <8r%_ ']
2}I1z_dq~
C/_W>H_
//启动子线程 O,9KhX+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b V;R}3)
for(int i=0;i<nStartPos.length;i++) yZ6560(q
{ A#2Fd7&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n`0}g_\q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $C(}
nStartPos,nEndPos,i); @?G.6r~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8K6yqc H
fileSplitterFetch.start(); tQz-tQg
} N\HOo-X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WK/Byd.Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 98Pt&C?-B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a,M7Bbx
nEndPos = " + nFileLength); <G\q/!@_
// fileSplitterFetch[nPos.length-1].start(); Q>JJI:uC4
:%xiH%C>
gHvxmIG
//等待子线程结束 /S\P=lcb
//int count = 0; 1/6G&RB
//是否结束while循环 vy1:>N?#5
boolean breakWhile = false; Po(9BRd7
gAgzM?A1(
noOG$P#
while(!bStop) Mh[;E'C6
{ LJfd{R1y+
write_nPos(); !4]wb!F
Utility.sleep(500); ui YZk3
breakWhile = true; q*?LXKi
/u*((AJ?Qv
#r#UO
for(int i=0;i<nStartPos.length;i++) ^0ipM/Lg
{ C:l /%
if(!fileSplitterFetch.bDownOver) hqD]^P>l1
{ C{-e(G`Yd
breakWhile = false; b)3dZ*cOJ
break; <k6Zx-6X<
} ZnI_<iFR*
} g"hm"m}i
if(breakWhile) a%7%NN*i
break; jzdK''CHi
Z-*L[
M7fw/i
//count++; *s S7^OZ*
//if(count>4) %W+*)u72(
// siteStop(); !d&K,k
} GO+cCNMa"
z6ArSLlZ
EUu"H` E+
System.err.println("文件下载结束！"); +i4S^B/8i
} }O<=!^Y;A
catch(Exception e){e.printStackTrace ();} %mt|Dl
} 3!,XR\`[
iaLsIy#h
Zh6bUxr
//获得文件长度 pI,QkDJ0
public long getFileSize() TmoODG>@
{ ,L6d~>=41
int nFileLength = -1; GTeFDm;T^
try{ >ys>Q)
URL url = new URL(siteInfoBean.getSSiteURL()); w(eAmN:zR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iLws;3UX;x
httpConnection.setRequestProperty("User-Agent","NetFox"); co|jUDu>W
@vCPX=c
4=%Uv^M
int responseCode=httpConnection.getResponseCode(); ,<d[5;7x
if(responseCode>=400) q+>{@tP9
{ m5v9:5{
processErrorCode(responseCode); Zq}w}v
return -2; //-2 represent access is error 6 GO7[?U<
} m`}! dBi
8G6PcTqv"
-shS?kV
String sHeader; ZXY5Xvt:v
8&IsZPq%l
(I IPrW;>
for(int i=1;;i++) %r=uS.+hrF
{ 7*r Q6rAP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3qXOsa7
//Utility.log(in.readLine()); <_dyUiT$J
sHeader=httpConnection.getHeaderFieldKey(i); `kpX}cKK}
if(sHeader!=null) \|F4@
{ hJ (Q^Z
if(sHeader.equals("Content-Length")) 5IOOVYl
{ `|XE B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [V|,O'X ~
break; rh5R kiF~
} _[<R<&jG
} >8"oO[U5>
else r1\c{5Wt
break; 'nz;|6uC
} j\B]>PP5
} osoreo;V^
catch(IOException e){e.printStackTrace ();} hq6B pE
catch(Exception e){e.printStackTrace ();} &na#ES$X,
=;W"Pi;*
.0:BgM
Utility.log(nFileLength); rjo/-910
D^baXp8
J}c57$Z
return nFileLength; wZJpSkcEx
} ug'I:#@2
#g#vDR!
#v0"hFOH,
//保存下载信息（文件指针位置） *p`0dvXG2
private void write_nPos() /`Yy(?,
{ 5Q#;4
try{ Kfa7}f_
output = new DataOutputStream(new FileOutputStream(tmpFile)); Wb+^Ue
output.writeInt(nStartPos.length); #=V%S 2~
for(int i=0;i<nStartPos.length;i++) e6z;;C@'G
{ lM86 *g 'l
// output.writeLong(nPos); K_{f6c<
output.writeLong(fileSplitterFetch.nStartPos); HJhPd#xCW
output.writeLong(fileSplitterFetch.nEndPos); jL(=<R(~y
} -wH#B<'
output.close(); }fpK{db
} nfJ|&'T
catch(IOException e){e.printStackTrace ();} >@KQ )p' `
catch(Exception e){e.printStackTrace ();} kTb.I;S
} <W~5;m
(o~f6pNB,
bY|%ois4
//读取保存的下载信息（文件指针位置） #+N\u*-S
private void read_nPos() bE#=\kf|
{ IfzHe8>
try{ veFl0ILd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gtd!Y x
int nCount = input.readInt(); zpV@{%VSj
nStartPos = new long[nCount]; 9I0/KuZd O
nEndPos = new long[nCount]; `zGK$,[%
for(int i=0;i<nStartPos.length;i++) 3$ cDC8
{ =2] .G Gg
nStartPos = input.readLong(); a*REx_gLG
nEndPos = input.readLong(); ]W7(}~m
} a/;u:"
input.close(); M[}EVt~
} q>/# P5V
catch(IOException e){e.printStackTrace ();} blNE$X+0|
catch(Exception e){e.printStackTrace ();} $e&( ncM
} 9!b,!#=
(f#QETiV
)SQ*"X4"
private void processErrorCode(int nErrorCode) ?BT\)@h
{ L+LxS|S+M
System.err.println("Error Code : " + nErrorCode); Vc.A<(
} vo)pT
X&o!xV -+
[t*m$0[:
//停止文件下载 u*B.<GmN
public void siteStop() .j:.?v
{ fzO4S^mTo8
bStop = true; 8J{I6nPF
for(int i=0;i<nStartPos.length;i++) 8>S"aHt 7
fileSplitterFetch.splitterStop(); L&=j O0_
A`v(hBM
P*oKcq1R
} j}uFp|df<
} `2c>M\c4U
//负责部分文件的抓取 -CfGWO#Gbx
**FileSplitterFetch.java Zx,R6@l
*/ ZKzXSI4
package NetFox; :*gYzk8
aehGT|
!`q*{Ojx
import java.io.*; EF=.L{
import java.net.*; OSk:njyC[
lE:X~RO"~
Xoyk 'T]-
public class FileSplitterFetch extends Thread { RBIf6oxdE
#u~s,F$De
=]&?(Gq
String sURL; //File URL LI_>fuv"8
long nStartPos; //File Snippet Start Position ^'.=&@i-
long nEndPos; //File Snippet End Position sUN>uroi !
int nThreadID; //Thread's ID >8Wvz.Nq/
boolean bDownOver = false; //Downing is over JYL/p9K[I
boolean bStop = false; //Stop identical $gT+Ue|7
FileAccessI fileAccessI = null; //File Access interface jXvGL
3p{N7/z(
)k01K,%#)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :LBG6J
{ lS]<~
this.sURL = sURL; $3S6{"
this.nStartPos = nStart; fI>>w)5
this.nEndPos = nEnd; ?#!Hm`\.
nThreadID = id; kKVd4B[#*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qp 4.XL
} n"vl%!B
a]'sby
F+,X%$A#?
public void run() JW9^C
{ ,X(P/x{B
while(nStartPos < nEndPos && !bStop) 8*kZ.-T B
{ )QE7$|s
*cxmQ
?(Q" y\
try{ tt%Zwf
URL url = new URL(sURL); r?Jxl<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); # eqt{
httpConnection.setRequestProperty("User-Agent","NetFox"); F,Y,0f@4U9
String sProperty = "bytes="+nStartPos+"-"; VvN52 qeL
httpConnection.setRequestProperty("RANGE",sProperty); <$wh@$PK
Utility.log(sProperty); ATCFdtNc
"<ow;ciJF
In^MZ)?
InputStream input = httpConnection.getInputStream(); 0cZyO$.
//logResponseHead(httpConnection); dl;~-'0
p 2xOjS1
*F*c
byte[] b = new byte[1024]; D5fJuT-bp
int nRead; W/ZmG]sZE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H=])o21
{ !R;P"%PHV
nStartPos += fileAccessI.write(b,0,nRead); '#$Y:/
//if(nThreadID == 1) <h|XB}s+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VTk6.5!8
} <J-bDcp
6TJ5G8z_
;Q&38qI
Utility.log("Thread " + nThreadID + " is over!"); <GPL8D
bDownOver = true; ~R/w~Kc!/A
//nPos = fileAccessI.write (b,0,nRead); $V-]DD%Y
} r_p9YS@I
catch(Exception e){e.printStackTrace ();} r9z_8#cR
} 6~zR(HzV{
} }HtP8F8!x
w{k8Y?
5,`U3na,
//打印回应的头信息 EJ{Z0R{{
public void logResponseHead(HttpURLConnection con) Ze~$by|9f
{ j*f%<`2`j
for(int i=1;;i++) kB1]_v/
{ :khl}|
String header=con.getHeaderFieldKey(i); )V~Fl$A
if(header!=null) ;~T)pG8IS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j}XTa[
Utility.log(header+" : "+con.getHeaderField(header)); Q1EY!AV8
else #%z--xuJL
break; 0/hX3h
} *I%r
} jC+>^=J(
SjD,
iY"I:1l.
public void splitterStop() mN+~fuh
{ j[NA3Vj1P
bStop = true; Je_Hj9#M\d
} +#8?y 5~q
QwXM<qG*
Hn)K;?H4
} c:I1XC
yveyAsN`B
Yf.H$L
/* uW%7X2K
**FileAccess.java 9qD/q?Hh$
*//文件访问(定位，写) ~ z4T
package NetFox; v:1l2Y)g
import java.io.*; >"?HbR9
uA=6 HpDB
;5^grr@,4
public class FileAccessI implements Serializable{ *V#v6r7<Y/
UXD?gK1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7Z5,(dH>
RandomAccessFile oSavedFile; L(TO5Y]
long nPos; WS9n.opl}
zf$&+E-
2!>phE
public FileAccessI() throws IOException .vNfbYH(
{ Jpg_$~k
this("",0); ,e+.Q#r*Y
} *E0+!
D *W+0
dvxD{UH
public FileAccessI(String sName,long nPos) throws IOException /-z_"G
{ d=WC1"
oSavedFile = new RandomAccessFile(sName,"rw"); 1~8F&
this.nPos = nPos; z
oSavedFile.seek(nPos); 6yk
} St,IWOmq"
"F>-W\%
=bs4*[zq
public synchronized int write(byte[] b,int nStart,int nLen) F3jrJ+nJ
{ XOa<R
int n = -1; &=fBqod
try{ /eDah3%d
oSavedFile.write(b,nStart,nLen); R<LW*8
n = nLen; %_u*5,w
} :i0xer
catch(IOException e) a8M.EFa:
{ G+4a%?JH
e.printStackTrace (); 0K>rc1dy
} 9F0B-aZ
n4YEu\*
^T'+dGU`
return n; M_MiY|%V/K
} ~c ;7me.
@ :Q];rc
9;dP7o
} (HLy;^#R
!? ?Cxs'
;w4rwL
/* V'c9DoSRI\
**SiteInfoBean.java Fdd$Bl.&XS
*/ 8"wA8l.
package NetFox; "A__z|sQ
SAs'u"EB
tnqW!F~
public class SiteInfoBean { ./kmI#gaV
>IfJ.g"
t(lTXG
private String sSiteURL; //Site's URL l1jS2O(
private String sFilePath; //Saved File's Path X X{:$f+
private String sFileName; //Saved File's Name 2t1WbP1
private int nSplitter; //Count of Splited Downloading File v0X5`VV
'\1%%F7
Q9K Gf;
public SiteInfoBean() R.A}tV=j#
{//nSplitter的缺省值为5 ec1snMY
//default value of nSplitter is 5 r!Eo8C
this("","","",5); Y8.0R-:ZAN
} j='Ne5X1
_+|*
fouy??
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '7>Vmr6
{ QC4_\V>[
sSiteURL= sURL; tt|U,o
sFilePath = sPath; AEPgQ9#E
sFileName = sName; :L:;~tK
this.nSplitter = nSpiltter; zQ]IlMt
j /-p3#c
)t&|oQ3sVG
} ~SM2W%
\'E_
b_V)]>v+
public String getSSiteURL() QI=SR
{ rC_K L
return sSiteURL; =eac,]31
} =6
z&<Rx[
P_-zkw
public void setSSiteURL(String value) +hjc~|RK
{ V$q%=Sip
sSiteURL = value; U{>!`RN
} >ID 3oi
5`x9+XvoN
UeHS4cW
public String getSFilePath() lBQ|=
{ rUlpo|B
return sFilePath; 'U1r}.+b>
} D:n0dfPU
wO8^|Yf
<@*mFq0,
public void setSFilePath(String value) 9-Ib+/R0
{ lS?f?n^
sFilePath = value; MM'<uy
} d/t'N-m
-2 tZ
`R:<(:
public String getSFileName() Q7=J[,V:2
{ y9s5{\H
return sFileName; q<hN\kBs
} /cI]Z^&
k[vn:
vZ]gb$
public void setSFileName(String value) KOF!a
{ VKik8)/.
sFileName = value; pQVi&(M
} WM@uxe,
<wE2ly&x
RtqW!ZZ:H
public int getNSplitter() B.Xm*adBT
{ ,{oP`4\Lm
return nSplitter; W_sDF; JP
} "X]ufZ7
//LXbP3/
-3 W4
public void setNSplitter(int nCount) 8L=QfKr
{ x<ENN>mW1
nSplitter = nCount; :A[bqRqe
} ww\/$ |
} k*!J,/=k
B=Zo0p^
jNIM1_JjD
/* '6/uc:zv
**Utility.java ~NTpMF
*/ nIsi
package NetFox; p:4vjh=1h
W_DO8nX
v>nJy~O]
public class Utility { 10[~ki-1;
$C[YqZO
a,j!B hu
public Utility() "lz!'~im
{ yTDoS|B+)
U{O\
4a3f!G$
} M1ayAXO
sdO;vp^:b
//线程睡眠 6iC}%eU
public static void sleep(int nSecond) 2j"%}&
{ n]o+KT\
try{ hh8UKEM-
Thread.sleep(nSecond); 17 j7j@s)
} ]&r/H17
catch(Exception e) N{q'wep
{ S`6'~g
e.printStackTrace (); jr9ZRHCU
} 3p^WTQ>(
} d&ZwVF!
4\$Ze0tv
//日志 {UUVN/$
public static void log(String sMsg) C/cGr)|8%
{ }pTj8Tr
System.err.println(sMsg); -B4v1{An
} rmhCuY?f
_c(=>
'<}7bw}+c
public static void log(int sMsg) !^LvNW\|
{ L,D!T&B
System.err.println(sMsg); kfVG@o?o
} Tbwq_3fK
} w_{z"VeD
7}lZa~/
NMj`wQ`M+
/* HOUyB's'
**TestMethod.java /f6]XP\'`+
*/ Zq`bd55~
package NetFox; ,v6Jr3
nQP0<_S
N%_~cR;
public class TestMethod { Y7jD:P
(la
txgGL'
public TestMethod() Dr2h-
{ ///xx/weblogic60b2_win.exe JA)gM
try{ [n}c}%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lZua"Ju
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #k"[TCQ>
SiteFileFetch fileFetch = new SiteFileFetch(bean); xUw\Y(!
fileFetch.start(); -w2ga1
} Bdg*XfXXk
catch(Exception e){e.printStackTrace ();} M84LbgGM%
a-}%R
54;iLL
} |knP
:^*V[77
vV'^HD^v
public static void main(String[] args) iwVra"y
{ K;97/"
new TestMethod(); Xo*$|9[.
} R5i8cjKZ?w
} QP;b\11m
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