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)); eN>=x40
} "pdG%$
for(int i=0;i<nEndPos.length-1;i++) _zJY1cr
{ :Ff1Js(Z
nEndPos = nStartPos[i+1]; -#3B>VY
} 9g"a`a?c
nEndPos[nEndPos.length-1] = nFileLength; \PU|<Ru.
} Y!i4P#4+q
} tAP~
Hh$D:ZO
|g> K$m^
//启动子线程 fcr\XCG7U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !K'kkn,h
for(int i=0;i<nStartPos.length;i++) :b^tu8E
{ (BMFGyE3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cf<i"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vwZ2kk!|i
nStartPos,nEndPos,i); qB3 SQ:y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>;U1Wt
fileSplitterFetch.start(); 0u QqPF t
} b,D+1'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), & @^|=>L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DDN#w<#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5Tb93Q@c
nEndPos = " + nFileLength); }OI;M^5L
// fileSplitterFetch[nPos.length-1].start(); 65=i`!f
N#C,_ k
#`);UAf
//等待子线程结束 7O;v5k~iQ
//int count = 0; u_e}m>[S
//是否结束while循环 h<6@&yzp
boolean breakWhile = false; ?t'O\n)M
j9) Z'L
:v Pzw!
while(!bStop) F_zs"ex/
{ TaG'?
write_nPos(); 3@KX|-
Utility.sleep(500); |6"zIHvtc
breakWhile = true; D"bLJj/!
xO'1|b^&
/=lrdp!a
for(int i=0;i<nStartPos.length;i++) 3Q~ng2Wv%
{ puL1A?Y8UM
if(!fileSplitterFetch.bDownOver) -"\z|OQ
{ bf'@sh%W
breakWhile = false; 9FX'Uws
break; 4ZQXYwfC|
} P[8`]=
} [US.n+G6
if(breakWhile) fwf]1@#
break; FX+Ra@I!
HMS9_#[kE
fE|([` !
//count++; M!,$i
//if(count>4) Y=x]'3}^
// siteStop(); 7zgU>$i
} $a(wM1S4
[FAoC3 k-h
+<"sC+2
System.err.println("文件下载结束！"); 9-Qub+0o
} IpB0~`7YI
catch(Exception e){e.printStackTrace ();} |mc!v*O
} x>!#8?-h
Av_1cvR:
PLw;9^<
//获得文件长度 p(v+j_ak
public long getFileSize() ^E{~{
{ *'QD!Tc
int nFileLength = -1; @Ej{sC!0T
try{ i.)kV B
URL url = new URL(siteInfoBean.getSSiteURL()); Jf|J":S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F[l{pc "C
httpConnection.setRequestProperty("User-Agent","NetFox"); ]{0 2!
F9]GEBLr
{O]Cj~}
int responseCode=httpConnection.getResponseCode(); DKF`uRvGN:
if(responseCode>=400) )4D |sN
{ &xj?MgdNL
processErrorCode(responseCode); = =cAL"Z
return -2; //-2 represent access is error 8qrE<RHU@
} i?A4uyYwS
:jT1=PfL
{Tm31f(oD
String sHeader; ](aXZ<,
Z'/:
]Yp;8#:1
for(int i=1;;i++) bs kG!w
{ -nV]%vJ$R}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :&/'rMi<T
//Utility.log(in.readLine()); #:v|/2
sHeader=httpConnection.getHeaderFieldKey(i); w=rh@S]
if(sHeader!=null) =CFO]9
{ >IJH#>i
if(sHeader.equals("Content-Length")) :,fs'!
{ 8)\ ?6C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;xN4L
break; 38tRb"3zP
} dK#:io[Nz
} lN<vu#
else TXv3@/>ZlG
break; E"b+Q
} y['$^T?oP
} {uM*.]
catch(IOException e){e.printStackTrace ();} 'Wn'BRXq3
catch(Exception e){e.printStackTrace ();} \@N8[
^Cst4=:W
!.?2zp~
Utility.log(nFileLength); quTM|>=_R
^r?ZrbSbz
}Cvf[H1+
return nFileLength; VA&_dU]*
} jav7V"$
>KNiMW^V
]t=m
//保存下载信息（文件指针位置） K pDKIi
private void write_nPos() MD1n+FgTu
{ QaH32(iH
try{ 5*/~) wN\U
output = new DataOutputStream(new FileOutputStream(tmpFile)); -v/1R1$e1
output.writeInt(nStartPos.length); Ovxs+mQ
for(int i=0;i<nStartPos.length;i++) Nz'fMdaX,
{ pi*cO
// output.writeLong(nPos); N<zD<q
output.writeLong(fileSplitterFetch.nStartPos); *Ew`Fm H
output.writeLong(fileSplitterFetch.nEndPos); (oBvpFP33
} bg'Qq|<U
output.close(); o+*YX!]#L
} p`fUpARA!
catch(IOException e){e.printStackTrace ();} F/tGk9v
catch(Exception e){e.printStackTrace ();} AU -,
} A_tdtN<
Q( U+o-
&GGJ=c\
//读取保存的下载信息（文件指针位置） |C301ENZ
private void read_nPos() 8d?r )/~
{ jdiH9]&U
try{ _D1Uc|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7?9QlUO
int nCount = input.readInt(); !i,Eo-[Z
nStartPos = new long[nCount]; vO`~rUA
nEndPos = new long[nCount]; v-B{7 ~=#Z
for(int i=0;i<nStartPos.length;i++) <U%4$83$
{ U>H"N1
nStartPos = input.readLong(); r7+"i9
nEndPos = input.readLong(); 7hQXGY,q
} InBnU`(r
input.close(); sG7G$G*ta!
} WWhAm{m
catch(IOException e){e.printStackTrace ();} h6Ovl
catch(Exception e){e.printStackTrace ();} o,>9|EMQZ
} Z@2^> eC
(HbA?Aja
mM0VUSy
private void processErrorCode(int nErrorCode) S~()A*5
{ wXZ"}uT<}
System.err.println("Error Code : " + nErrorCode); uH="l.u
} F$.h+v
Rsd~t_a1
lHerEv<ja
//停止文件下载 O?L6Ues
public void siteStop() He vZ}.
{ a> qB k})
bStop = true; (yA`h@@WS
for(int i=0;i<nStartPos.length;i++) v7gs $'Q
fileSplitterFetch.splitterStop(); /*Iq,"kGz
$ha,DlN
]s_,;PGU
} bca4'`3\|
} $$F iCMI
//负责部分文件的抓取 /|Z_Dy
**FileSplitterFetch.java i]x_W@h
*/ ) rw!. )
package NetFox; xs,,)jF(u
CoZOKRoaH
^%ZbjJ7|j
import java.io.*; IJ\4S
import java.net.*; q>|&u
"QSmxr
/M!b3bmA
public class FileSplitterFetch extends Thread { qQjd@J}^
$0 ]xeD0X
>vQ8~*xd
String sURL; //File URL 8! eYax
long nStartPos; //File Snippet Start Position OD[q u
long nEndPos; //File Snippet End Position lldNIL6B%
int nThreadID; //Thread's ID M5 \flE2
boolean bDownOver = false; //Downing is over SG\6qE~
boolean bStop = false; //Stop identical *).u:>D4
FileAccessI fileAccessI = null; //File Access interface AS4mJ UU9
4}4cA\B:n
tE'^O< K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DpQ\q;
{ =T!eyGE
this.sURL = sURL; 59Lc-JJ
this.nStartPos = nStart; p{|!LcSU$2
this.nEndPos = nEnd; f[}(E
nThreadID = id; %9vl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DwmK?5p
} sg`
(yrN-M4~t
:3b.`s(M
public void run() cYmgJBG
{ Th_PmkvC
while(nStartPos < nEndPos && !bStop) B@w/wH
{ /_SQKpic
ibH!bS{
^?J3nf{
try{ HTz5LAe~b7
URL url = new URL(sURL); ZSWZz8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;gGq\c
httpConnection.setRequestProperty("User-Agent","NetFox"); or,:5Z
String sProperty = "bytes="+nStartPos+"-"; wxJu=#!M
httpConnection.setRequestProperty("RANGE",sProperty); =E.!Ff4~(
Utility.log(sProperty); MB7`'W
~Uw;6VXV1
.jUM'; l
InputStream input = httpConnection.getInputStream(); rjK]zD9
//logResponseHead(httpConnection); )E|{.K
H2lQ(Y+H
; DXsPpZC
byte[] b = new byte[1024]; ff&jR71E
int nRead; -wa"&Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @yM$Et5
{ @U+#@6
nStartPos += fileAccessI.write(b,0,nRead); /|0xOiib
//if(nThreadID == 1) p0rmcP1Ln
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LXoZ.3S
} F[(ocxQZ3
E)%DLZ
+pPfvE`
Utility.log("Thread " + nThreadID + " is over!"); ?wP/l
bDownOver = true; `G0k)eW
//nPos = fileAccessI.write (b,0,nRead); BItH0r7
} RDfvD|}VN
catch(Exception e){e.printStackTrace ();} (/7b8)g
} o_8Wnx^
} &%]v0QK
iC{(vL0P+
H-rxn
//打印回应的头信息 NX4G;+6
public void logResponseHead(HttpURLConnection con) c=,HLHpFO(
{ Al1_\vx7
for(int i=1;;i++) n:|a;/{I]9
{ ]"/SU6#4:
String header=con.getHeaderFieldKey(i); E+ctiVL
if(header!=null) 8eVy*h2:=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gky+.EP.
Utility.log(header+" : "+con.getHeaderField(header)); ZIN1y;dJ
else ,eGguNA9
break; GKc?
} 7KesfH?
} u*f`\vs
/WGD7\G'8
q68CU~i*
public void splitterStop() L{&>,ww
{ N5c*#lHI
bStop = true; jG~-V<&
} :i4AkBNK
0K'{w]Q
5vFM0
} $l2`@ia"
9a[1s|>w-
0W0GSDx
/* vw 6$v
**FileAccess.java `dw">z,
*//文件访问(定位，写) egK~w8`W%
package NetFox; "cyRzQ6EH
import java.io.*; (gnN</%
Atb`Q'Yrw
XV/7K"
public class FileAccessI implements Serializable{ ~s-bA#0S
7]} I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R?zlZS.~
RandomAccessFile oSavedFile; idB1%?<
long nPos; eL>wKu:r
-:95ypi
j!@T@ 8J
public FileAccessI() throws IOException ~/X8Hy!-
{ vf zC2
this("",0); XHxJzYMc
} >?1GJ5]\s
udT0`6l;
fF(AvMsO
public FileAccessI(String sName,long nPos) throws IOException DXG`%<ZMn
{ ZJF"Yo
oSavedFile = new RandomAccessFile(sName,"rw"); %%F,G
this.nPos = nPos; Ell14Iki
oSavedFile.seek(nPos); m62Zta
} w[F})u]E
v-N4&9)%9
O}%ESAB
public synchronized int write(byte[] b,int nStart,int nLen) s>:gL,%c
{ /Yb8= eM
int n = -1; tmOy"mq67
try{ *xJ]e.
oSavedFile.write(b,nStart,nLen); `v@Z|rv,
n = nLen; X&HYWH'@,
} -. o,bg
catch(IOException e) Fm=jgt3wv8
{ ia3Q1 9r
e.printStackTrace (); :1Nc6G
} etT9}RbQ
\?oT.z5VG&
z Ohv>a
return n; 71@kIJI
} CcW3o"=4
A +=#
2<9K}Of
} z{&Av
ZJW8S
uB^"A ;0v
/* %19~9Tw
**SiteInfoBean.java pdm(7^
*/ ,}\LC;31,
package NetFox; ^SsdM#E
tH&eKM4G
[<5/s$,i
public class SiteInfoBean { yZ7)|j
Vpp$yM&?
dH.Fb/7f
private String sSiteURL; //Site's URL hxj\
private String sFilePath; //Saved File's Path l?$X.CwX
private String sFileName; //Saved File's Name 6eUGE4NF(
private int nSplitter; //Count of Splited Downloading File M*bsA/Z
w>\oz
j94~cYV
public SiteInfoBean() O'B3sy
{//nSplitter的缺省值为5 +,,dsL
//default value of nSplitter is 5 .wp[uLE
this("","","",5); cLp_\\
} 5=8v\q?)c
G~DHNO6
50dN~(;p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IP$eJL[&D"
{ rz,,ku4qt
sSiteURL= sURL; 8\9W:D@"x
sFilePath = sPath; kP}l"CN4
sFileName = sName; Y'jgp Vt
this.nSplitter = nSpiltter; 9mp`LT
~CHcbEWk)W
|EdEV*.ej
} n:B){'S
%z.V$2
y`8U0TE3R
public String getSSiteURL() Ym"^Ds}
{ I L7kpH+y
return sSiteURL; Du +_dr^4
} QHja4/
WF*j^ %5
?$ov9U_
public void setSSiteURL(String value) Dq%}({+
{ )7!,_r
sSiteURL = value; %QrOEs
} ^!C
x^c,cV+*
c%O97J.5b
public String getSFilePath() }"nm3\Df
{ !SE
return sFilePath; `n-/~7
} J"< h#@`
FeS ,TQ4j
}f_@@#KB?
public void setSFilePath(String value) RhmkpboucC
{ J @~g>
sFilePath = value; o3\^9-jmp
} 6iXV
?./fVoA]V
+w(6#R8u5
public String getSFileName() \!jz1`]&{
{ IY6Qd4157
return sFileName; TD*AFR3Oz
} ^tSwAanP\
h?;03>6A&]
A@?-"=h}
public void setSFileName(String value) x4>"m(&%
{ -6WSYpHV
sFileName = value; AxH`4=3<
} BMQ4i&kF|
x5xMr.vm
}@jJv||
public int getNSplitter() qhG2j;
{ ReD]M@;
return nSplitter; 4;)t\9cy_
} ^\ln8!;
^8bc<c:P
YahW%mv`d
public void setNSplitter(int nCount) T`j{2
{ 55TFBDc
nSplitter = nCount; pO fw *lD
} Het>G{
} 6C<GYzzo
%XBTN
N"RPCd_
/* XYD-5pG
**Utility.java b;*'j9ly
*/ <Piq?&VX[
package NetFox; ZybfqBTD&c
Wl=yxJu_(
TG8U=9qt
public class Utility { m5] a
*kZH~]
(4RtoYWW
public Utility() 7!(/7U6rP
{ pRxVsOb
~*\ *8U@7
"Xwsu8~
} G(shZ=fq
3G 5xIr6
//线程睡眠 (RrC<5"
public static void sleep(int nSecond) o(> #}[N}
{ Z eY*5m
try{ 1#;^Z3
Thread.sleep(nSecond); =_3rc\0
} b&QI#w
catch(Exception e) SYQP7oG9oQ
{ KRn[(yr`%
e.printStackTrace (); yKK9b
} wxBZ+UP_
} xzfugW
XV4aR3n{Q
//日志 ~#VDJ[Z
public static void log(String sMsg) _ MB/p
{ m~W[,7NE0&
System.err.println(sMsg); #u+qV!4
} f-H"|9
b KIL@AI
%qE"A6j
public static void log(int sMsg) FL^t}vA
{ VK,{Mu=.9
System.err.println(sMsg); {[/A?AV;F
} *qLk'<
} mea} 9]c
@x A^F%(
:yi} CM4
/* |=~mRqG
**TestMethod.java lfd-!(tXD
*/ v$JW7CKA
package NetFox; v+trHdSBYE
cUd>ahv
jLO$[c`;
public class TestMethod { j"pyK@v2B
5! +{JTXa
n)D
public TestMethod() 3QVUWhJ
{ ///xx/weblogic60b2_win.exe +O8zVWr
try{ BG.8 q4[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T*C F5S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z!fbc#L6
SiteFileFetch fileFetch = new SiteFileFetch(bean); ypemp=+(r
fileFetch.start(); -`z%<)!Y
} >o`+j$j
catch(Exception e){e.printStackTrace ();} UH+#Nel+!
qkp0'f*}
$T66%wX
} o /1+ }f
0Y0`$
X&rsWk
public static void main(String[] args) <4@8T7
{ m#O; 1/P
new TestMethod(); (]&B'1b
} 9H:J&'Xi7
} Zy?!;`c*{
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