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)); R(i2TAaaU
} -{ae
for(int i=0;i<nEndPos.length-1;i++) +IRr&J*P
{ =LFrV9
nEndPos = nStartPos[i+1]; +c8cyx:^f
} =nq9)4o
nEndPos[nEndPos.length-1] = nFileLength; lbRm(W(
} Hy?+p{{G
} iva?3.t
SGZ]_
B/iRR2h
//启动子线程 v7V.,^6+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UL46%MFQ\
for(int i=0;i<nStartPos.length;i++) P ~pC /z
{ |L@9qwF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Zr'Mn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GN7\p)
nStartPos,nEndPos,i); {3jV ,S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #Cwzk{p(
fileSplitterFetch.start(); S$=e %c
} IT.'`!T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A3\%t@y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /c`s$h4-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RpAtd^I
nEndPos = " + nFileLength); EB/.M+~a
// fileSplitterFetch[nPos.length-1].start(); !Q`vOVSUD
af:wg]g
LC!ZeW35
//等待子线程结束 H-*"%SJ
//int count = 0; _$W</8<
//是否结束while循环 5i 6*$#OM_
boolean breakWhile = false; c]pO'6]
nA!Xb'y&
w&M)ws;$
while(!bStop) Uf:G,%OYi
{ NXwlRMbo
write_nPos(); H%K,2/Nj
Utility.sleep(500); zF&>1y.$
breakWhile = true; vYYLn9}5
jq4'=L$4
208dr*6U
for(int i=0;i<nStartPos.length;i++) 7\BGeI
{ Ik92='Z
if(!fileSplitterFetch.bDownOver) [jOvy>2K]
{ >%~E <
breakWhile = false; UF g N@
break; N+<`Er
} )$# Ku2X
} pB3dx#l
if(breakWhile) vd4}b>
break; GM5s~,
" <GDOL
)u. ut8![T
//count++; 0@ -3U{Q
//if(count>4) \X'{ ee
// siteStop(); 9Q!X~L|\S
} lL*k!lNs
rKP;T"?;
~[J&n-bJU
System.err.println("文件下载结束！"); IT`r&;5
} )/'y'd<r
catch(Exception e){e.printStackTrace ();} /r4QDwu
} .js@F/Hp
bS0z\!1
-PHVM=:
//获得文件长度 7VP[U,
public long getFileSize() -?8;-h, h
{ x?ajTzMv
int nFileLength = -1; V9v80e {n4
try{ Eua\N<!aai
URL url = new URL(siteInfoBean.getSSiteURL()); c`'2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J,8Wo6
httpConnection.setRequestProperty("User-Agent","NetFox"); HWr")%EhD
~%6GF57gC
_&/FO{F@m
int responseCode=httpConnection.getResponseCode(); Ib)>M`J
if(responseCode>=400) HiBw==vlV
{ \#bk$R@
processErrorCode(responseCode); (_}w4N#
return -2; //-2 represent access is error x)X=sX.
} :v_H;UU
0]v:Ix
EM_`` 0^
String sHeader; /Z:\=0`
cuJ%;q=;
|eEcEu?/b
for(int i=1;;i++) t~xp&LQiY
{ -{ Ng6ntS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WQ\H2go
//Utility.log(in.readLine()); YN\!I
sHeader=httpConnection.getHeaderFieldKey(i); `-l,`7e'
if(sHeader!=null) /4\!zPPj.
{ RH,1U3?
if(sHeader.equals("Content-Length")) (6C%w)8'
{ 9zj^\-FA_l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *siN#,5
break; |[k/%
} uvo2W!
} E(i<3U"4h[
else =O qw`jw
break; )~q@2^
} ~-+lZ4}
} V 0<>Xo%
catch(IOException e){e.printStackTrace ();} c}nXMA^^
catch(Exception e){e.printStackTrace ();} #,dE)
Pg3O )D9
:y)'_p *l/
Utility.log(nFileLength); #ii,GN~N
C0\A
MQR@(>TZy
return nFileLength; I("J$
} b|i94y(
kaxAIk8l
GS^U6Xef
//保存下载信息（文件指针位置） Bc{#ia
private void write_nPos() =sG9]a<I
{ D0?l$]aE
try{ ~!c~jcq]lZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); _v2K1 1
output.writeInt(nStartPos.length); *i[^-
for(int i=0;i<nStartPos.length;i++) .P[ %t=W
{ Z3K~C_0Cnu
// output.writeLong(nPos); K0xZZ`
output.writeLong(fileSplitterFetch.nStartPos); &H!#jh\w
output.writeLong(fileSplitterFetch.nEndPos); sjLI^#a
} %J06]FG7
output.close(); h"S+8Y:1{k
} lY5a=mwHU
catch(IOException e){e.printStackTrace ();} rC>')`uk
catch(Exception e){e.printStackTrace ();} VWoxi$3v
} ]KMOLe6(
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;Ry )^5Q
//读取保存的下载信息（文件指针位置） Ly?yWS-x
private void read_nPos() 8=^o2&
{ (,<ti):
try{ gt3;Xi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hB#z8D
int nCount = input.readInt(); .7-Yu1{2
nStartPos = new long[nCount]; i"uAT$xe
nEndPos = new long[nCount]; g)+45w*+5
for(int i=0;i<nStartPos.length;i++) Aj06"ep
{ *N"bn'>3
nStartPos = input.readLong(); >r7{e:~q
nEndPos = input.readLong(); ZbJUOa?WF
} L3M]06y
input.close(); zT|]!',
} ms'!E)
catch(IOException e){e.printStackTrace ();} ]9?_m@Ihx
catch(Exception e){e.printStackTrace ();} jV^Dj
} ".z~c%'
`F:PWG`
CtwMMZXX3
private void processErrorCode(int nErrorCode) hS4Ljyeg
{ rIz"_r
System.err.println("Error Code : " + nErrorCode); 3Q^@!hu
} }}v04~
Xidt\08s
C[:Q?LE
//停止文件下载 6KmF 9
public void siteStop() KOWxP47b
{ #2c-@),
bStop = true; 372ewh3'
for(int i=0;i<nStartPos.length;i++) !7SZZz
fileSplitterFetch.splitterStop(); xq',pzN
/U[Y w)
\M/XM6:UG4
} ]@bo;.
} Sk@~}
//负责部分文件的抓取 DoA4#+RU
**FileSplitterFetch.java @RKw1$BA
*/ E)%]?/w
package NetFox; o>{+vwK
-\@&^e
T"-HBwl
import java.io.*; HUurDgRi]
import java.net.*; { hUbK+dKZ
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KLlo^1.<
public class FileSplitterFetch extends Thread { 6Gjr8
0V*L",9M
w5|az6wZB!
String sURL; //File URL bh:;ovH
long nStartPos; //File Snippet Start Position Nzz" w_#
long nEndPos; //File Snippet End Position ( 3IM7
int nThreadID; //Thread's ID s]0x^"#B
boolean bDownOver = false; //Downing is over LjjE(Yrv{
boolean bStop = false; //Stop identical R%XbO~{u
FileAccessI fileAccessI = null; //File Access interface FLY#
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N. 3 x[%:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nm66U4.@
{ lKEdpF<
this.sURL = sURL; v#:#w.]-Y
this.nStartPos = nStart; swuW6p
this.nEndPos = nEnd; GWRKiTu9
nThreadID = id; NMmk,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RUm1;MWs
} xlkEW&N&
Q$G!-y+"i
d@pD5n=m;
public void run() =dUeQ?>t=
{ Ra[{K@
while(nStartPos < nEndPos && !bStop) $Ne$s
{ tlu-zUsi
>F6'^9|
D#508{)
try{ =:mD)oX*
URL url = new URL(sURL); =yOIP@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [F%INl-sy
httpConnection.setRequestProperty("User-Agent","NetFox"); " GkBX
String sProperty = "bytes="+nStartPos+"-"; wz31e!/
httpConnection.setRequestProperty("RANGE",sProperty); <i`Ipj
Utility.log(sProperty); ([iMOE[D3
I0sd%'Ht?
{ :'#Ts<
InputStream input = httpConnection.getInputStream(); #g\O*oYaw
//logResponseHead(httpConnection); su>GeJiPW
o X )r4H?
QNJ )HNLp
byte[] b = new byte[1024]; +'Pf|S
int nRead; 5;oWFl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J,%v`A~N
{ j8WnXp_
nStartPos += fileAccessI.write(b,0,nRead); '@i/?rNi%N
//if(nThreadID == 1) &z8@ rk|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nAG2!2_8
} R}>xpU1
PsMoH/+"
d4t%/Uh
Utility.log("Thread " + nThreadID + " is over!"); @v\Osp t=
bDownOver = true; gUwg\>UC
//nPos = fileAccessI.write (b,0,nRead); Vb az#I
} .z4 fJx
catch(Exception e){e.printStackTrace ();} ;D&FZ|`(u
} *,q ?mO
} u6Fm qK]Dj
pSvRyb.K
3Cmbt_WV
//打印回应的头信息 fmrd7*MW
public void logResponseHead(HttpURLConnection con) 9`]Gosz
{ WcqQR))n
for(int i=1;;i++) dc.9:u*w
{ 3cfW|J
String header=con.getHeaderFieldKey(i); T'B43Q
if(header!=null) ?XN=Er^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `ECT8
Utility.log(header+" : "+con.getHeaderField(header)); z)p( l!
else |fqYMhA U
break; FFX-kS
} nb dm@
} uNSaw['0j
CAg~K[
qM78s>\-h
public void splitterStop() |`vwykhezO
{ z#9Tg"8]
bStop = true; 3kfrOf.4h
} Wd"<u2
-E{D'X
" E+V>V+
} 5"5!\Zo
BV)oF2b:
m#6RJbEz
/* z7TMg^9#
**FileAccess.java mbT4K8<^
*//文件访问(定位，写) N~NUBEKcp
package NetFox; 'kU5
import java.io.*; :jL>sGvBv
1OI/!!t1$
R 6JHRd
public class FileAccessI implements Serializable{ -wr#.8rzTT
0C!f/EZK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DR]=\HQ
RandomAccessFile oSavedFile; ZtHTl\z
long nPos; -YvnX0j+
zI-]K,!
((0nJJjz
public FileAccessI() throws IOException PY81MTv0;
{ w{F{7X$^
this("",0); <c'0-=
} |m{u]9
7slpj8
U]Y</>xGI
public FileAccessI(String sName,long nPos) throws IOException o6bT.{8\
{ aF8'^xF
oSavedFile = new RandomAccessFile(sName,"rw"); ZZ'5BfI"I%
this.nPos = nPos; <|-da&7
oSavedFile.seek(nPos); |WP}y-Au
} Q Ev7k
_(7f0p
w?#s)z4}g
public synchronized int write(byte[] b,int nStart,int nLen) SG$V%z"e
{ vJ,r}$H3
int n = -1; KBC?SxJSJc
try{ Gxhr0'
oSavedFile.write(b,nStart,nLen); i,V,0{$
n = nLen; XXDLbT'J
} x-nO; L-2p
catch(IOException e) &&PXWR!%]
{ >U\1*F,Om,
e.printStackTrace (); 'G>$W+lT^
} IL>VH`D
xeNj@\jdC5
= Ed0vw
return n; ;_X2E~i[
} { )g $
0u) m9eg
5Z@0XI
} rdH3!
]9$iUA%Ef
U9"(jl/o
/* ]?G|:Kx$y%
**SiteInfoBean.java Ce/l[v
*/ XCyU)[wY
package NetFox; {8* d{0l
;rRV=$y
4`e[gvh
public class SiteInfoBean { i 558&:
I>EEUQR/$H
j:2TicHDC
private String sSiteURL; //Site's URL g@2KnzD
private String sFilePath; //Saved File's Path .H@b zm
private String sFileName; //Saved File's Name 9-+N;g!q
private int nSplitter; //Count of Splited Downloading File Kn=0AdM
$35C1"
PrHoN2y5E
public SiteInfoBean() s*Nb=v.e9
{//nSplitter的缺省值为5 9OYyR
//default value of nSplitter is 5 \RqH"HqD
this("","","",5); 9.%t9RM^
} B:Y F|k}T
OO2uE ;( 3
h% eGtd$n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,!40\"A
{ M5a&eO
sSiteURL= sURL; GT7&>}FJ)
sFilePath = sPath; _\8jnpT:
sFileName = sName; ff;~k?L
this.nSplitter = nSpiltter; !bCSt?}@u
JZdRAL2#v
}Y^o("c(
} I_m3|VCa|t
+MZI\>
%VGW]!QR
public String getSSiteURL() YkFAu8b>
{ RFLfvD<
return sSiteURL; u`ryCZo#g
} aGd wuD
b"aF-,M>
qSGM6kb
public void setSSiteURL(String value) y/E:6w
{ OxPl0-]t
sSiteURL = value; 2!6E~<~HC
} k`;d_eW
K {kd:pr
^TD%l8o6
public String getSFilePath() UEx13!iFo
{ Y7zs)W8xTT
return sFilePath; #mU<]O
} =w* 8
ufe|I
ohbU~R3{U
public void setSFilePath(String value) Q}G2f4
{ qyxd9Lk1
sFilePath = value; E~#G_opQA
} 6J\ 2=c`
<(@Z#%O9)
{i+ o'Lw
public String getSFileName() _9]vlxgtG(
{ 8k3y"239t
return sFileName; R[14scV
} +;\w'dBi,
wAw1K2d
x|yJCs>
public void setSFileName(String value) $E&T6=Wn
{ zrqI^i"c
sFileName = value; X0iy
} 4/%fpU2
/@|iI<|
}S8aR:'
public int getNSplitter() +SF+$^T
{ 8h0CG]
return nSplitter; eAo+w*D(
} Pro?xY$E)
mI5J]hk
\i/HHP[%
public void setNSplitter(int nCount) f=k#o2
{ PJ;WNo8
nSplitter = nCount; <T?-A}0uO
} "0uM%*2
} Pjk2tf0j`
V'e%%&g~N
nShXY6bA
/* cE:s\hG
**Utility.java :{N*Z}]
*/ &ocuZ-5`
package NetFox; 6`7tTn?n
">.tPn
D{s87h
public class Utility { Zj!,3{jX^
V]; i$
1Xo0(*O
public Utility() y%ij)vQY
{ *~g*J^R}
hcj]T?
}3A~ek#*~
} YTFU#F
AwXzI;F^
//线程睡眠 cz,QP'g
public static void sleep(int nSecond) 'KIT^k0"Ih
{ o S=!6h
try{ %SOXw8-
Thread.sleep(nSecond); ;YR/7
} iAZ8Y/
catch(Exception e) _\KFMe=PV
{ `@ YV
e.printStackTrace (); Ij7P-5=<
} Fy"M 4;7
} }< H>9iJ:
SFRP ?s
//日志 u+Ix''Fn#%
public static void log(String sMsg) )I[f(f%W7
{ ttUK~%wSx
System.err.println(sMsg); IK\~0L;ozE
} Sc]K-]1(H
'o6}g p)
6w7;
public static void log(int sMsg) /^AH/,p
{ g}v](Q
System.err.println(sMsg); o[cOL^Xd1
} T8a' 6otc
} +Q u.86dH
GZ~Tl0U
##6\~!P
/* {ogBoDS
**TestMethod.java #zTy7ZS,0
*/ WVRIq'
package NetFox; -n.m "O3
gLX<>|)*
(DO'iCxlNh
public class TestMethod { Jz`jN~
ksC_F8Q+
3<&:av3
public TestMethod() -`I|=lBz{H
{ ///xx/weblogic60b2_win.exe &^"Ru?MK
try{ = g{I`u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bI &<L O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bFX{|&tHU
SiteFileFetch fileFetch = new SiteFileFetch(bean); SvM\9
fileFetch.start(); vHf)gi}O|
} GK}52,NM
catch(Exception e){e.printStackTrace ();} gS~H1Ro
:|s8v2am
rJ Jx8)M
} ^[7Mp
Qp:I[:Lr;
oIE 1j?
public static void main(String[] args) L*Z.T^h
{ Ei_~K';
new TestMethod(); pq{`WgA^
} G$>?UQ[
} .2fvRN92
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