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)); ?N<* ATCL
} 6]rIYc[,
for(int i=0;i<nEndPos.length-1;i++) MbC7`Sp&i
{ #.UooFk+Y
nEndPos = nStartPos[i+1]; Pfu2=2Ra
} }x`W+r
nEndPos[nEndPos.length-1] = nFileLength; K?,eIZ{.S
} g8 ,V( ^
} RyKsM.
kXA o+l
aErms-~
//启动子线程 \,i9m9;y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aG}ju;
for(int i=0;i<nStartPos.length;i++) : I28Zi*
{ m+||t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >xws
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gEbe6!; q3
nStartPos,nEndPos,i); a H'iW)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }(z[ rZ
fileSplitterFetch.start(); 6uW?xB9
} ,J"6(nk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;ajCnSmR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '{p/F $
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j1%o+#df
nEndPos = " + nFileLength); ;BUJ5
// fileSplitterFetch[nPos.length-1].start(); 4=td}%
CTQF+Oe8O
b26#0;i
//等待子线程结束 fi^I1*S
//int count = 0; b[<r+e8
//是否结束while循环 l7]:b8
boolean breakWhile = false; %>Z^BM<e
l^w=b~|7=
-"[o|aa^
while(!bStop) |} ;&xI
{ X:bv ?o>Y
write_nPos(); h`X)sC+
Utility.sleep(500); j}3Avu%
breakWhile = true; orYE&
G=/a>{
a7s+l=
for(int i=0;i<nStartPos.length;i++) l5QH8eNwME
{ z^$DXl@)h
if(!fileSplitterFetch.bDownOver) Yb\t0:_
{ nfET;:{
breakWhile = false; KWbnSL8
break; ma[%,u`
} O*xC}$OOn
} u9My.u@-*%
if(breakWhile) P&"8R
break; hJ$o+sl
Xptb4]
6MQ+![fN
//count++; gR}>q4b
//if(count>4) l{ja2brX
// siteStop(); JpqZVu"7
} u+%Ca,6
/~[+'
$mOVo'2
System.err.println("文件下载结束！"); 4^cDp!8
} g"aWt% P
catch(Exception e){e.printStackTrace ();} ^F2OTz4n
} $51M'Qu
6t/nM
L[o;@+32
//获得文件长度 m}&cXY
public long getFileSize() yW5/Y02
{ i3#To}g5V
int nFileLength = -1; &<hDl<E
try{ n+1!/H=d
URL url = new URL(siteInfoBean.getSSiteURL()); XCr\Y`,Z@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5p!X}u]
httpConnection.setRequestProperty("User-Agent","NetFox"); w/_n$hX
vU,AOK[l{
C_xOk'091
int responseCode=httpConnection.getResponseCode(); -5;Kyio
if(responseCode>=400) !lxs1!:
{ 8>^(-ca_
processErrorCode(responseCode); C><]o
return -2; //-2 represent access is error .,Qj3
} eS)2#=
uG<VQ2LM
W*?mc2;/
String sHeader; CR8a)X4j#
Z3jh-{0
}*eiG
for(int i=1;;i++) |m{Q_zAB
{ 8 Z|c!QIU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [MLJs-*
//Utility.log(in.readLine()); >d#oJ?goX
sHeader=httpConnection.getHeaderFieldKey(i); YDh6XD<Z
if(sHeader!=null) R-odc,P=
{ L(Ww6oj
if(sHeader.equals("Content-Length")) mBWE^
{ 70pt5O3]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eyq\a'tyB
break; &XG k
} kkWqP20q
} w&&uk[Gh/a
else *;^!FBT
break; .gY}}Q
} 6x18g(KbP
} X^204K%:
catch(IOException e){e.printStackTrace ();} C-25\
catch(Exception e){e.printStackTrace ();} )gM3,gSS
WKVoqp}
zx)^!dEMM
Utility.log(nFileLength); [t)omPy<c
W5'07N^
b _Q:v&
return nFileLength; $BIQ#T>qK
} W?+U%bIZ9
OPm?kr
g7*"*%v 2
//保存下载信息（文件指针位置） F\pw0^K;N
private void write_nPos() $7Sbz&)y3
{ si`{>e~`6P
try{ @q=l H *=
output = new DataOutputStream(new FileOutputStream(tmpFile)); JiFy.Pf
output.writeInt(nStartPos.length); W40GW
for(int i=0;i<nStartPos.length;i++) oL?[9aww
{ t:A,pT3
// output.writeLong(nPos); 00DWXGt20o
output.writeLong(fileSplitterFetch.nStartPos); $#Mew:J
output.writeLong(fileSplitterFetch.nEndPos); 1-z*'Ghys
} t<`h(RczHI
output.close(); In1VW|4h
} FN$hEc!
catch(IOException e){e.printStackTrace ();} 'vgO`
catch(Exception e){e.printStackTrace ();} NF?FEUoxz
} ,p(4OZz5,
sU7>q}!
>;E[XG^
//读取保存的下载信息（文件指针位置） TF\<`}akX
private void read_nPos() sOyWsXd+R'
{ iz|mJUx
try{ Z=;+) #,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |.bp
int nCount = input.readInt(); TmN}TMhZ
nStartPos = new long[nCount]; >{DHW1kF?
nEndPos = new long[nCount]; fVR:m`'Iq_
for(int i=0;i<nStartPos.length;i++) @G/':N
{ $}[Tj0+:
nStartPos = input.readLong(); P1PP#>E-2
nEndPos = input.readLong(); Salu[)+?
} [\9WqHs
input.close(); xP@VK!sc
} ` eB-C//
catch(IOException e){e.printStackTrace ();} 1[k~*QS
catch(Exception e){e.printStackTrace ();} mwuFXu/
} KR
X^3 0a*sj
^V^In-[!y:
private void processErrorCode(int nErrorCode) =hV-E D
{ V/j]UK0$
System.err.println("Error Code : " + nErrorCode); S}"?#=Q.%O
} >40B Fxc
Q:LyD!at
gbc^Lb
//停止文件下载 ^q"wd?((h
public void siteStop() qA- ya6
{ M/U$x /3K
bStop = true; &}Y_EHj}
for(int i=0;i<nStartPos.length;i++) y$)gj4k/D
fileSplitterFetch.splitterStop(); Q9K+k*?{N
0F'75
9Ao0$|@b
} {GF>HHQb
} ^qpa[6D6x
//负责部分文件的抓取 mB(*)PwZ
**FileSplitterFetch.java B0c}5V
*/ i'!M<>7
package NetFox; .?SClTqg
}?P~qJ|1
~L(_q]
import java.io.*; c ;3bX6RD*
import java.net.*; PN:8H>
v9~Hl
[5%/{W,~m
public class FileSplitterFetch extends Thread { (4V1%0
{d$S~
X.0/F6U
String sURL; //File URL ,8(%J3J
long nStartPos; //File Snippet Start Position !DnG)4#
long nEndPos; //File Snippet End Position KmV>tn BQ
int nThreadID; //Thread's ID - Pz )O@ ;
boolean bDownOver = false; //Downing is over ^_<>o[qE
boolean bStop = false; //Stop identical IidZ-Il
FileAccessI fileAccessI = null; //File Access interface l,/q#)5[
$8&HpX#h$
rL URP2~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y? [*qnPj
{ T[))ful
this.sURL = sURL; Zn3iLAPBX
this.nStartPos = nStart; QnxkD)f*0
this.nEndPos = nEnd; gb:Cc,F,%
nThreadID = id; Fga9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @{_PO{=\C
} yZ:|wxVY
cFLu+4.jsG
Cu({%Gy+
public void run() ^JtGT
{ hBsjO3n
while(nStartPos < nEndPos && !bStop) whNRUOK:
{ ZP)=2'RY
Y,D\_il_
,Ucb)8a
try{ HZQI|
URL url = new URL(sURL); }jd[>zk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pmCBe6n\l
httpConnection.setRequestProperty("User-Agent","NetFox"); i/xPO
String sProperty = "bytes="+nStartPos+"-"; HqgTu`
httpConnection.setRequestProperty("RANGE",sProperty); :kZ2N67
Utility.log(sProperty); p!'wOThO`
z@y* jT
@6*<Xs =
InputStream input = httpConnection.getInputStream(); y<F$@
//logResponseHead(httpConnection); z!Kadqns
hl~(&D1^
5d}PrYa
byte[] b = new byte[1024]; "4"\tM(
int nRead; CjQ_oNI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +:&(Ag
{ 3:Co K#
nStartPos += fileAccessI.write(b,0,nRead); =mqV&FgRo
//if(nThreadID == 1) lO, 2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j<deTK;.
} b&~uK"O'7d
%o4d43uZ
C`mXEX5
Utility.log("Thread " + nThreadID + " is over!"); ^e>v{AE%
bDownOver = true; 4v2(YJ%u
//nPos = fileAccessI.write (b,0,nRead); (kp}mSw
} ZJ=C[s!wu
catch(Exception e){e.printStackTrace ();} EZP2Bb5g
} 0nie>
} D3.sR\Hxf
%n}.E304
oU~V0{7g
//打印回应的头信息 L&3=5Bf9
public void logResponseHead(HttpURLConnection con) uFdSD
{ !W$Br\<
for(int i=1;;i++) 62(WZX%b
{ |P?8<8p
String header=con.getHeaderFieldKey(i); [RpFC4W
if(header!=null) p'w[5'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [F/xU
Utility.log(header+" : "+con.getHeaderField(header)); 9:~,TH
else Zl,K#
break; OD1ns
} * n!0
} O1#rCFC|y
hChM hc
; wHuL\
public void splitterStop() [z$J
{ La9@h"
bStop = true; 3al5Vu2:
} *fd` .}
E"G._<3J8
?tA-`\E
} G~esSL^G/
J"83S*2(j
0_]aF8j
/* 0)2lBfHQ&
**FileAccess.java wG{obsL.!
*//文件访问(定位，写) VGvOwd)E
package NetFox; G,"$Erx
import java.io.*; V)(pe #P
w@:o:yLS
Osy5|Ts
public class FileAccessI implements Serializable{ =kc{Q@Dk
t3s}U@(C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JnsXEkM)
RandomAccessFile oSavedFile; gSe{S
long nPos; moo>~F _^
mmjB1L
t!iF(R\
public FileAccessI() throws IOException wUV%NZB
{ U73`HDJ
this("",0); 73<iK]*c
} qJ!oH&/cD
e5XikLu
sN?:9J8
public FileAccessI(String sName,long nPos) throws IOException YJL=|v
{ X1'Ze,34
oSavedFile = new RandomAccessFile(sName,"rw"); { o;0Fx
this.nPos = nPos; ih;TQ!c+b
oSavedFile.seek(nPos); aEM#V
} /6.b>|zF
JWdG?[$
/nmfp&@
public synchronized int write(byte[] b,int nStart,int nLen) +es6c')
{ %4-pw|':
int n = -1; hBqu,A
try{ #62ww-E~
oSavedFile.write(b,nStart,nLen); AdYQhF##
n = nLen; |$w-}$jq5
} ~ dk1fh
catch(IOException e) Ce)Wvuh
{ jXDo!a|4y
e.printStackTrace (); 2bC%P})m
} PJ.jgN(r
pxC5a i
?-Z:N`YP
return n; KWH
} Arv8P P^'
YOoP]0'L
1M{#"t{6
} t&uHn5
lKwcT!Q4
>k jJq]A2
/* S\rfR N
**SiteInfoBean.java {2Ibd i
*/ ;5l|-&{@*
package NetFox; _t[%@G>P
!Yf0y;e|:
l85"C
public class SiteInfoBean { dEp=;b s
hzH5K
!Ch ya
private String sSiteURL; //Site's URL x M[#Ah)
private String sFilePath; //Saved File's Path H}~^,B2;
private String sFileName; //Saved File's Name OE"Bb
private int nSplitter; //Count of Splited Downloading File tSYnc7
{ULnQ6@
K!~](_W!
public SiteInfoBean() 9|m L
{//nSplitter的缺省值为5 ]]ZBG<#
//default value of nSplitter is 5 5~F0'tb|}
this("","","",5); T{M:)}V
} F&~vD
pp`U]Q5"gX
Jp#cFUa t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `QF|> N
{ h:NXO'
sSiteURL= sURL; /{va<CL
sFilePath = sPath; /0uinx
sFileName = sName; eH8.O
this.nSplitter = nSpiltter; &$Lm95
iT"Itz-^#
*)1z-rH`
} Qa%SvA@R
(jG$M=q-
J_@4J7
public String getSSiteURL() M2S|$6t:
{ yw<xv-Q=i
return sSiteURL; D=vq<X'
} 2cl~Va=
t} M3F-NZ
J|IDnCK
public void setSSiteURL(String value) do,X{\
{ LfApVUm
sSiteURL = value; S@)bl
} XEEbmIO*<9
<hbbFL}|%
U8KY/!XZ
public String getSFilePath() s`YuH <8
{ F! e`i-xt
return sFilePath; TbVL71c
} ^'4uTbxP_!
QEKFuY<E+
bl<7[J.
public void setSFilePath(String value) z;fSd
{ . 6dT5x8u
sFilePath = value; lz 6 Aj
} r|@?v,
m5X=P5U
Se8y-AL6x>
public String getSFileName() `.g8JC\_m
{ K;y\&'E
return sFileName; CK</2w+
} Z(M)2
}0RFo96)v
9Q/!%y%5
public void setSFileName(String value) .*blM1+6i/
{ gj^]}6-P
sFileName = value; [#Vr)\n
} pQ{t< >
w"iZn
uLljM{I
public int getNSplitter() OvG0UXRU
{ *,*qv^
return nSplitter; iGk{8Da<
} {B.]w9
y3]"H(
%ko 8P
public void setNSplitter(int nCount) :<8V2
{ 8v 1%H8
nSplitter = nCount; Z-a(3&
} yZ$;O0f&&
} ?/MXcI(
~[q:y|3b
gDNW~?/
/* 66^t[[
**Utility.java ^)l@7XxD
*/ @|Bp'`j%J
package NetFox; J)|K/W9
_|:bac8pL
U&$]?3?
public class Utility { pw yl,A
wR4u}gb#q
"Cj#bUw
public Utility() i6 ?JX@I
{ guXpHF=
{OrE1WHB
r.^X>?
} "]Dzc[Vp
l:yAgm`
//线程睡眠 z.HNb$;
public static void sleep(int nSecond) bnu0*Zg>
{ {; cB?II
try{ 6G$tYfX
Thread.sleep(nSecond); H)aC'M^
} @zF:{=+]+
catch(Exception e) u!k<sd_8B
{ 72vGfT2HtZ
e.printStackTrace (); =e-aZ0P
} x>"JWD
} TbAdTmW
XPo'iI-
//日志 igj@{FN
public static void log(String sMsg) *"{Z?< 3
{ \1C!,C
System.err.println(sMsg); bk9~63tN+>
} .hNw1~Fj
N:jiZ)
n12c075
public static void log(int sMsg) P\6T4s
{ ^GaPpm
System.err.println(sMsg); ~.`r(
} Ny7=-]N4{"
} V?dK*8s
g] C3lf-
LEnP"o9ZW
/* 7h&`BS
**TestMethod.java =1OAy`8
*/ `4$Qv'X*
package NetFox; ":^ NLBm>5
i3&B%JiLX
)K%O/H
public class TestMethod { Fd,+(i D
q.sQ Z]ty9
Bp{`%86SE
public TestMethod() 7+hF;
{ ///xx/weblogic60b2_win.exe ~w9=Fd6
try{ y{I[}$k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8 E+C:"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yxWMatZ2
SiteFileFetch fileFetch = new SiteFileFetch(bean); SJc@iffS
fileFetch.start(); KM(9&1/
} 9Y@?xn.\
catch(Exception e){e.printStackTrace ();} 9`n)"r
S@zkoj@
{2gd4[:
} -Dq:Y,%q
q;0&idYC
9f%y)[ \
public static void main(String[] args) O0(Q0Ko
{ F@'rP++4
new TestMethod(); {%~4RZA
} C 3XZD4.2
} o"}&qA;
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