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)); ",\,lqV
} *jps}uk<
for(int i=0;i<nEndPos.length-1;i++) $~|#Rz%v
{ 94umk*ib
nEndPos = nStartPos[i+1]; pm-SDp>s
} ptS1d$
nEndPos[nEndPos.length-1] = nFileLength; )|88wa(M
} 2[W1EQI
} ubn`w=w$
H}OOkzwrA
i>n.r_!E
//启动子线程 tH_e?6]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rRN7HL+b
for(int i=0;i<nStartPos.length;i++) @iZ"I i&+
{ 0ivlKe%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BTXS+mvl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (GVH#}uB
nStartPos,nEndPos,i); kMGK8y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OIK14D:
fileSplitterFetch.start(); Zc"Vf]:
} paUlp7x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'sCj\N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YlW~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5} 9}4e
nEndPos = " + nFileLength); D:9/;9V
// fileSplitterFetch[nPos.length-1].start(); =(f+geA"hm
47R4gs#W
AnV\{A^
//等待子线程结束 &C eG4_Mi
//int count = 0; 4~Ptn/ g
//是否结束while循环 a1;P2ikuK
boolean breakWhile = false; x/NR_~Rnk
(vCMff/ Y1
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while(!bStop) CKShz]1
{ xkIRI1*!
write_nPos(); ~c>*3*
Utility.sleep(500); FE+Y#
breakWhile = true; 6&o9mc\I
K-&&%Id6R
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for(int i=0;i<nStartPos.length;i++) d,fX3
{ ,6,sz]3-
if(!fileSplitterFetch.bDownOver) -c-#1_X5
{ ;P9P2&c8c
breakWhile = false; bkQEfx.
break; s? /#8 `
} NZ(c>r6
} ecK{+Z'G
if(breakWhile) adG=L9 "n
break; E|ce[|2
9$&+0
N=J$+
//count++; U$[C>~r
//if(count>4) SST1vzm!
// siteStop(); 2ZMYA=[!
} d'~sy>
GE`:bC3
t?NB#/#%x
System.err.println("文件下载结束！"); Mg H,"G
} G1 ?."
catch(Exception e){e.printStackTrace ();} AtRu)v6r
} (fmcWHs
d\aarhD8*
P+iZ5S\kL=
//获得文件长度 ?{s!.U[T@
public long getFileSize() d52l)8
{ PI>PEge!&
int nFileLength = -1; R:zPU
try{ *')g}2iB
URL url = new URL(siteInfoBean.getSSiteURL()); sY4sq5'!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2s,[DC
httpConnection.setRequestProperty("User-Agent","NetFox"); vn"2"hPF|
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zzsQfI#
int responseCode=httpConnection.getResponseCode(); (Dr g
if(responseCode>=400) LG6VeYe|\X
{ xaO9?{O
processErrorCode(responseCode); -%]O-'
return -2; //-2 represent access is error 8'Dp3x^W>
} M17oAVN7D
laX(?{_
BZy&;P
String sHeader; yjZ]_.
5~T`R~Uqb
J&4QI( b.
for(int i=1;;i++) 70,V>=aJ
{ 7;dTQ.%n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y,&UST
//Utility.log(in.readLine()); J(*qOGBD
sHeader=httpConnection.getHeaderFieldKey(i); NvH9?Ek"
if(sHeader!=null) Xz)UH<
{ @xKLRw
if(sHeader.equals("Content-Length")) ji(W+tQ2Y'
{ Q3MG+@)S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5b X*8H D
break; ?!>B}e&,
} T"1H%65`V
} [Nb0&:$ay
else 12 HBq8o
break; lqFDX d
} =;DmD?nZ
} ;-p1z% u
catch(IOException e){e.printStackTrace ();} 9"Vch;U$
catch(Exception e){e.printStackTrace ();} nU]n]gd
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`>CHE'_
Utility.log(nFileLength); [+0rlmB
dz fR ^Gv
}gL:"C"~
return nFileLength; n< UuVu
} L><# I
>|%dN jf@Q
4Q2=\-KFj
//保存下载信息（文件指针位置） pG?AwB~@n
private void write_nPos() q)%F#g
{ &phers
try{ SN!TE,=I
output = new DataOutputStream(new FileOutputStream(tmpFile)); i^j1i
output.writeInt(nStartPos.length); z-<091,
for(int i=0;i<nStartPos.length;i++) E(DNK
{ *Ag</g@ h
// output.writeLong(nPos); pME17 af
output.writeLong(fileSplitterFetch.nStartPos); O@;;GJ
output.writeLong(fileSplitterFetch.nEndPos); e?W-vi%
} shjc`Tqm
output.close(); ~`'!nzP5H
} :s8^nEK
catch(IOException e){e.printStackTrace ();} 8S2sNpLi-g
catch(Exception e){e.printStackTrace ();} FEqs4<}E
} VOc_7q_=
]IbX<
MD(?Wh
//读取保存的下载信息（文件指针位置） [RtTi<F^
private void read_nPos() F?!P7 zW
{ %LBa;M
try{ 3IXai)6U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H;('h#=cD
int nCount = input.readInt(); }Rujh4*
nStartPos = new long[nCount]; HUF],[N
nEndPos = new long[nCount]; H4%2"w6|!
for(int i=0;i<nStartPos.length;i++) y/}[S@4uB
{ Hc?8Q\O:
nStartPos = input.readLong(); Dep.Qfv{-
nEndPos = input.readLong(); <9zzjgzG{c
} ,(d\!T/]'
input.close(); &)UZ9r`z
} ${(v Er#}k
catch(IOException e){e.printStackTrace ();} !|!k9~v!
catch(Exception e){e.printStackTrace ();} USF9sF0l
} Z(Styn/x
~s.~X5
0ws1S(pq
private void processErrorCode(int nErrorCode) UQq,Xq
{ 1'.SHY|
System.err.println("Error Code : " + nErrorCode); +tsF.Is!t
} k'O^HMAn!
0,1x- yD
"Zk# bQ2j
//停止文件下载 ,4kly_$BH
public void siteStop() MA}~bfB
{ L{;Sc_
bStop = true; G]Rb{v,r
for(int i=0;i<nStartPos.length;i++) Po(Y',xI[
fileSplitterFetch.splitterStop(); i.QS(gM
kV>[$6
GnAG'.t-Z
} @bPR"j5D
} Eb 8vnB#
//负责部分文件的抓取 K1`Z}k_p.
**FileSplitterFetch.java 0tA~Y26
*/ X#;n Gq)5
package NetFox; d|I_SI1
UA>3,|gV1
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import java.io.*; b/#SkxW#S
import java.net.*; &xhwx>C`K
'3%JhG)#
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public class FileSplitterFetch extends Thread { @= E~`
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[z:.52@!
String sURL; //File URL #%Hk-a=>)#
long nStartPos; //File Snippet Start Position _v/w ,z
long nEndPos; //File Snippet End Position C~e&J&zh
int nThreadID; //Thread's ID ^$FNu~|K
boolean bDownOver = false; //Downing is over fAEgrw%Ti
boolean bStop = false; //Stop identical $7bLw)7
FileAccessI fileAccessI = null; //File Access interface Cs:?9G
<K g=?wb
P}`|8b1W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >m$jJlAv8
{ _h6j, )
this.sURL = sURL; !+UU[uM
this.nStartPos = nStart; K20,aWBq;3
this.nEndPos = nEnd; R"wBDWs
nThreadID = id; UC e{V]T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LoUHStt
} }4uHT.)
a/\SPXQ/9
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public void run() 2Kkm-#p7
{ -/V,<@@T
while(nStartPos < nEndPos && !bStop) F_U9;*f]
{ '2S/FOb
|2Vhj<6
Y9/`w@"v
try{ m&PB5s\=
URL url = new URL(sURL); qnu<"$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o5@d1A
httpConnection.setRequestProperty("User-Agent","NetFox"); elqm/u
String sProperty = "bytes="+nStartPos+"-"; =:M/hM)#
httpConnection.setRequestProperty("RANGE",sProperty); vh$If0
Utility.log(sProperty); \?D~&d,a=
m >Rdsn~l
=.`:jZG
InputStream input = httpConnection.getInputStream(); "u.'JE;j
//logResponseHead(httpConnection); ~GLWhe-
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+F?}<P_v
byte[] b = new byte[1024]; _v#Vf*#
int nRead; dc dVB>D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l\/uXP?
{ S.zY0
nStartPos += fileAccessI.write(b,0,nRead); 1!%T<!A.
//if(nThreadID == 1) qyKI.X3n*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'uW&ADp
} | |u
[t6Y,yo&h4
2@6Qifxd@
Utility.log("Thread " + nThreadID + " is over!"); Al3*? H&
bDownOver = true; ,bxGd!&{Q
//nPos = fileAccessI.write (b,0,nRead); ;=UkTn}N?l
} wX4gyr
catch(Exception e){e.printStackTrace ();} zcy`8&{A<?
} nb\pBl
} o?g9Grk
}*P?KV (
K0{ ,*>C
//打印回应的头信息 2M>`W5
public void logResponseHead(HttpURLConnection con) #Q1 |]
{ eJ0Xfw%y%T
for(int i=1;;i++) qoP/`Y6
{ g5;Ig
String header=con.getHeaderFieldKey(i); m@y<wk(
if(header!=null) >|pN4FS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KJ7-Vl>
Utility.log(header+" : "+con.getHeaderField(header)); <c&Nm_)
else hK UK#xx
break; #0f6X,3
} (@Kc(>(: Y
} :CsrcT=
,YBe|3
4iv&!hAc;
public void splitterStop() Mt*V-`+\
{ d f j;e%H
bStop = true; F@b=S0}K
} Ae;mU[MK/
I uC7Hx`z
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} A[`2Mnj
P}"T3u\N
**.g^Pyc
/* AqT}^fS
**FileAccess.java T7^?j :kJ/
*//文件访问(定位，写) 6!C>J#T
package NetFox; 3TRG] 5
import java.io.*; \cdns;
_`.Q7
!ou;yE&<,
public class FileAccessI implements Serializable{ s &f\gp1
oS~;>]W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s`|KT&r
RandomAccessFile oSavedFile; <rFh93
long nPos; mRy0zN>?
M6j~`KSE
Y(Y#H$w
public FileAccessI() throws IOException vwzElZ{C:v
{ +(Jh$b_
this("",0); kz G W/
} buDz]ec b
iZ4"@G:,
wlEK"kKU
public FileAccessI(String sName,long nPos) throws IOException }lP`3e
{ !gcea?I
oSavedFile = new RandomAccessFile(sName,"rw"); - LB}=
this.nPos = nPos; Fd<eh(g9P
oSavedFile.seek(nPos); (|pM^+
} dl(!{tZ#
Ed+jSO0
7~SnY\B|
public synchronized int write(byte[] b,int nStart,int nLen) gfKv$~
{ $}fY B/
int n = -1; hrGX65>
try{ i v.G
oSavedFile.write(b,nStart,nLen); viJP6fh
n = nLen; q0b*#j
} 0lOR.}]q
catch(IOException e) 211V'|a_>
{ )iJv?Y\]
e.printStackTrace (); _M^^0kf
} d5`D[,]d
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LQR^lD+_=
return n; ]0g p.R
} Cu_-QE
s~ou$!|
;/H/Gn+
} Gzs$0Ki=
<+<Nsza
j<R&?*
/* *U$%mZS]1
**SiteInfoBean.java de;CEm<n
*/ 5hh6;)
package NetFox; li{!Jp5]1b
y;(G%s1
?<S fhjU
public class SiteInfoBean { IVVX3RI
qlnA7cK!
:, 3S5!(y
private String sSiteURL; //Site's URL saDu'SmYV
private String sFilePath; //Saved File's Path KT17I&:
private String sFileName; //Saved File's Name nPDoK!r'
private int nSplitter; //Count of Splited Downloading File p 16+(m
R&$fWV;'
0g~Cdp
public SiteInfoBean() qJ .XI
{//nSplitter的缺省值为5 rU(-R@["
//default value of nSplitter is 5 qe22 kE#
this("","","",5); EB@rIvUi,
} L$rr:^J
bnPhhsR
|>1#)cONW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,6o tm
{ ig .
sSiteURL= sURL; gdg``U;)p
sFilePath = sPath; 8'NT_NPNb
sFileName = sName; i29a1nD4Hm
this.nSplitter = nSpiltter; Z[0/x.pp$
P]OUzI,
fn.;C
} M?o_J4
TuaP
VF b
public String getSSiteURL() r'lANl-v
{ EWY'E;0@5
return sSiteURL; ~|N,{GaL
} X?;iSekI4
$RunGaX!=N
iXWB
public void setSSiteURL(String value) G]{^.5
{ >_G'o
sSiteURL = value; lR9uD9Dr
} |.$7.8g
cV_-Bcb
Oi]B%Uxy=
public String getSFilePath() t;-F]
{ *B84Y.df
return sFilePath; )heHERbJ
} 4%|r$E/TQ
!H<%X~|,
I6gduvkXi4
public void setSFilePath(String value) cSNeWJKA6
{ wh2E$b(-
sFilePath = value; Aa]3jev
} cMoJHC,!
z.?slYe[
M4CC&?6\
public String getSFileName() >oaL-01i
{ Azp!;+
return sFileName; "WO0rh`
} Fs(S!;
qZ +K4H
@`8a3sL)
public void setSFileName(String value) B#35)QI
{ jA[")RVG
sFileName = value; 8OO[Le]1
} NV@$\<
O6ugN-d>
q)KOI`A
public int getNSplitter() H*+7{;$
{ eH[i<Z
return nSplitter; K{V.N</
} |JP'j1 Ka
Df:/r%
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public void setNSplitter(int nCount) R,=8)OI2
{ (0.JoeA`y
nSplitter = nCount; i\gt @
} T:9M|mD
} |F<%gJ
F- u"zox
o)x&|0_
/* 7Cbr'!E\_V
**Utility.java W:6#0b"_#
*/ Dhfor+Epy
package NetFox; q(L.i)w$
7~'%ThUb$-
fX6pW%Q'6
public class Utility { "a33m:]J
?4Fev_5m
rc~)%M<[2
public Utility() 1$6 u
{ mH5>50H;
{?EmO+![}
bn5O2
} +7nvy^m
SW+;%+`
//线程睡眠 8Q{9AoQ3'
public static void sleep(int nSecond) ^Jdg%U?
{ B,%KvL&xMX
try{ OYn5k6
Thread.sleep(nSecond); pv&iJ7RN
} F MYcZ+4
catch(Exception e) PxvxZJf$@
{ GK6CnSV8d
e.printStackTrace (); BM)a,fIgo
} }1+2&Ps50
} f~TkU\Rh
D!Nc&|X^
//日志 zxx9)I@?A
public static void log(String sMsg) WX_g
{ X.,R%>O}`P
System.err.println(sMsg); ~|ZAS]
} $AMcU5^b7
K V?+9qa,
^T1caVb|>
public static void log(int sMsg) nU\.`.39 +
{ >uQjygjj
System.err.println(sMsg); ]VtP7Y
} *8yC6|wL?
} b].U/=Hs
wgvCgr<
v4uQ0~k~X
/* e7&RZ+s#wZ
**TestMethod.java f4NN?"W)
*/ @KLX,1K
package NetFox; Az#kE.8b*A
,pf\g[tz
t U~q4$qqE
public class TestMethod { ]*U; }
9(vp`Z8B4
~HT:BO$
public TestMethod() (I>SqM Y
{ ///xx/weblogic60b2_win.exe -y?ve od#
try{ w+5OI9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oblw!)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mRGr+m
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y(EF )::
fileFetch.start(); VAyAXN~
} Lk^bzW>f
catch(Exception e){e.printStackTrace ();} c5O8,sT
X9^q-3&60
fLSDt(c',
} (r}StR+
pjSM7PhQ
qxZf!NX5
public static void main(String[] args) ^r7KEeVD
{ $`0,N_C<}
new TestMethod(); F4Cq85#
} 2@HmZ!|Q
} 9fM=5
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