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)); 7@a\*|K6
} [gn[nP9
for(int i=0;i<nEndPos.length-1;i++) vHc#m@4o
{ 3+zzi
nEndPos = nStartPos[i+1]; `^%@b SE(
} Tk](eQsy.v
nEndPos[nEndPos.length-1] = nFileLength; PUKVn+h
} A:)sg!Lt
} #ovM(Mld
xVTo4-[p
2Fq=jOA)z$
//启动子线程 A^L?_\e6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e^WqJ7j
for(int i=0;i<nStartPos.length;i++) 5L3{w+V
{ ' &N20w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qK-qcPLsl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L!vWRwZwC
nStartPos,nEndPos,i); W0?JVtq0Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |*1xrM:v~
fileSplitterFetch.start(); r\RFDj
} >#?iO]).
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Om6Mmoqh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); niAZ$w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WKOI\
nEndPos = " + nFileLength); c/RT0xql*
// fileSplitterFetch[nPos.length-1].start(); RNe9h lr
i'iO H|s
nF|Oy0
//等待子线程结束 Z9f/-|r5
//int count = 0; <M305BH
//是否结束while循环 B G5X_s0/
boolean breakWhile = false; /+29.1#|
]CIe~q
E4Zxv*
while(!bStop) Iu%^*K%
{ Iht'e8)gq
write_nPos(); O$U}d-Xnx
Utility.sleep(500); 4znH$M>bU
breakWhile = true; C$_G'XI
8=pv/o
A$ J9U3+O
for(int i=0;i<nStartPos.length;i++) R.O
{ ?-S8yqe
if(!fileSplitterFetch.bDownOver) wA1Ey:q
{ 0}D-KvjyP
breakWhile = false; OOfyGvs
break; []=_<]{
} T;J7+0
} $)f"K
if(breakWhile) i0b.AA
break; 8XlU%a6x
zF?31\GOX
gY%OhYtF2
//count++; @o60c
//if(count>4) ?0uOR*y'
// siteStop(); (HPz
} ovbEmb
+\srZ<67
3jXR"@Z-
System.err.println("文件下载结束！"); J ZA*{n2
} e|JIrOnc
catch(Exception e){e.printStackTrace ();} e) ]RA?bF
} pbPz$Y
[0wP\{%
dDo6fP2
//获得文件长度 i`R(7Z
public long getFileSize() m^'~&!ba
{ :q(D(mK
int nFileLength = -1; B_!wutV@
try{ 'OG{*TDPu
URL url = new URL(siteInfoBean.getSSiteURL()); NtqFnxm/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &jt02+Hj'
httpConnection.setRequestProperty("User-Agent","NetFox"); x ~wNO/
=pyVn_dg
jmSt?M0.xV
int responseCode=httpConnection.getResponseCode(); z+ uL "PG[
if(responseCode>=400) }'PG!+=I
{ Etw~*
processErrorCode(responseCode); & \JLTw
return -2; //-2 represent access is error MCM/=M'y
} O/(3 87=U
\zBd<H4S:
+)?,{eE|
String sHeader; z}iSq$
Qg[heND
b$dBV}0 L
for(int i=1;;i++) 8>ESD}(
{ >B`Cch/'U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t?KUK>>w
//Utility.log(in.readLine()); zf`5>h|
sHeader=httpConnection.getHeaderFieldKey(i); -Sx0qi'%
if(sHeader!=null) aXX,Zu^
{ o T:j:n
if(sHeader.equals("Content-Length")) h,]tQ#!s8
{ z/)$D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tc"T}huypU
break; )ni"qv~J
} u IAZo;
} DQ%`v=
else c!.=%QY
break; X{#bJ
} 7qpzk7X?pR
} 9z+vFk`
catch(IOException e){e.printStackTrace ();} 0,:iE\
catch(Exception e){e.printStackTrace ();} $|rCrak;
[+y&HNf
h]<GTWj
Utility.log(nFileLength); _cR6ik zW(
NS h%t+XU]
3T"2S[gT
return nFileLength; Pa3{Ds
} I+*osk
B^H4Q 4-
6euR'd^Qi
//保存下载信息（文件指针位置） 1]"D%U=
private void write_nPos() 2@rp<&s
{ _MGNKA6JI
try{ MgHOj
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]U_5\$
output.writeInt(nStartPos.length); [SK2x4
for(int i=0;i<nStartPos.length;i++) G}182"#4
{ C\y[&egww
// output.writeLong(nPos); 2=jd;2~
output.writeLong(fileSplitterFetch.nStartPos); ~azF+}x90N
output.writeLong(fileSplitterFetch.nEndPos); 43+EX.c
} f#*h^91x
output.close(); ,NjX&A@
} 2j2mW>Z
catch(IOException e){e.printStackTrace ();} Y,3z-Pa=@
catch(Exception e){e.printStackTrace ();} u9esdOv
} Dq{:R
~&t!$
DxE(9j
//读取保存的下载信息（文件指针位置） ,?C|.5
private void read_nPos() &/ \O2Aw8
{ CR%D\I$o
try{ c$@`P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xq+!eOT
int nCount = input.readInt(); VEL:JsY
nStartPos = new long[nCount]; 2O?Vr" A
nEndPos = new long[nCount]; g7.7E6%H
for(int i=0;i<nStartPos.length;i++) ll^Th >
{ C/SapX
nStartPos = input.readLong(); sGXp}{E9
nEndPos = input.readLong(); f1)HHUB
} F~tm`n8Z
input.close(); E%-Pyg*
} 3yeK@>C
catch(IOException e){e.printStackTrace ();} ;gZwQ6)i
catch(Exception e){e.printStackTrace ();} 2b; rr
} &r&;<Q
V*~1,6N[
+= X).X0K
private void processErrorCode(int nErrorCode) v]B0!k&4.
{ ~sZqa+jB0
System.err.println("Error Code : " + nErrorCode); `6|i&w:b
} l R:Ok8e
t.3Ct@wK
3?!G-
//停止文件下载 1_N~1Ik
public void siteStop() z8 hTZU
{ 99\{!W
bStop = true; |Dl*w/n
for(int i=0;i<nStartPos.length;i++) }@3Ud' Y
fileSplitterFetch.splitterStop(); C4&U:y<ju
b7?U8/#'
MDMtOfe|
} SNQz8(O
} mgmWDtxN
//负责部分文件的抓取 Ah6wU|_-g
**FileSplitterFetch.java pWWL{@J
*/ %4?SY82
package NetFox; qFvg}}^y
~5lKL5w
_<u8%\
import java.io.*; vpZu.#5c
import java.net.*; @N,:x\
;k9 ?
3r,1^h
public class FileSplitterFetch extends Thread { p:DL:^zx
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3!i.Fmo
String sURL; //File URL o?:;8]sr!
long nStartPos; //File Snippet Start Position ;X?Ah
long nEndPos; //File Snippet End Position TYs+XJ'Xj
int nThreadID; //Thread's ID =gxgS<bde
boolean bDownOver = false; //Downing is over vGx?m@
boolean bStop = false; //Stop identical #G'S ve?
FileAccessI fileAccessI = null; //File Access interface _myg._[
AyQS4A.s[
w8eG;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tQNk=}VR7r
{ Tns?mQ
this.sURL = sURL; Z7tU0
this.nStartPos = nStart; .`oJcJ
this.nEndPos = nEnd; b&\3ps
nThreadID = id; jF%)Bhn(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W&fW5af9
} @4 zi]v
ek<PISlci
hQgk.$g
public void run() ib5;f0Qa
{ :FX'[7;p
while(nStartPos < nEndPos && !bStop) +-Z"H)
{ ,pQ'w7
3::3r}g
DhtU]w}
try{ M/::`yJQu
URL url = new URL(sURL); an*]62l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fe& t-
httpConnection.setRequestProperty("User-Agent","NetFox"); ikEWY_1Y
String sProperty = "bytes="+nStartPos+"-"; g@S@d&9
httpConnection.setRequestProperty("RANGE",sProperty); !Z<mrr;T@
Utility.log(sProperty); X_lUD?y
/|4Q9=
dWzDSlP&
InputStream input = httpConnection.getInputStream(); Bo\a
//logResponseHead(httpConnection); WUE)SVf
=:xV(GK}
'Z*\1Ci
byte[] b = new byte[1024]; jI*}y[o
int nRead; QLn5#x~xb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %Y)PH-z
{ 5 {T9*
nStartPos += fileAccessI.write(b,0,nRead); EIq{C-(
//if(nThreadID == 1) q7 %=`l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b>hBct}
} T..N*6<X
hj^G}4
]p4`7@@)*
Utility.log("Thread " + nThreadID + " is over!"); `^XRrVX<
bDownOver = true; x'E'jh%
//nPos = fileAccessI.write (b,0,nRead); [?|l X$<
} lKh2LY=j
catch(Exception e){e.printStackTrace ();} N>&{Wl'y\
} P.[6s$J
} ?V&Ld$db
gmF_~"^34
ZYwBw:y}y
//打印回应的头信息 %5Q7#xU
public void logResponseHead(HttpURLConnection con) i#pjv'C
{ &y#\1K
for(int i=1;;i++) ^]#Ptoz^(l
{ [OFTP#}c
String header=con.getHeaderFieldKey(i); Pi&fwGL
if(header!=null) B|]t\(~$[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,(@Y%UW:
Utility.log(header+" : "+con.getHeaderField(header)); Dg9--wI}I9
else "k\Ff50
break; (c|$+B^*
} Jf%!I
} ,mO(!D
O+(. 29
Q{H!s_6iyv
public void splitterStop() 2 Ft0C2
{ XhlI|h-j
bStop = true; ;X*K*q
} zumR(<l
3X-{2R/ 3
%KabyvOl)
} g[=\KrTSg
7`uA
X <ba|(
/* `'G),{ j
**FileAccess.java $4$?M[
*//文件访问(定位，写) h8iaJqqvJ
package NetFox; O" X!S_R
import java.io.*; c"f-$^<
7(A G]
]HNT(w@
public class FileAccessI implements Serializable{ %T&&x2p^=?
}2iKi(io*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WL)_8!
RandomAccessFile oSavedFile; UZ4tq
long nPos; 4 BE:&A
]zhq.O >2{
wRV`v$*6
public FileAccessI() throws IOException %mB!|'K%
{ 8r`VbgI&
this("",0); =\Tud-1Z
} W[[YOK1T
YWcui+4p}
&P,4EaC9;
public FileAccessI(String sName,long nPos) throws IOException =B/s HN
{ 2#$}yP~
oSavedFile = new RandomAccessFile(sName,"rw"); QN2*]+/h
this.nPos = nPos; LhVLsa(-%
oSavedFile.seek(nPos); DiGUxnP
} uusY,Dt/9
:N*q;j>
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public synchronized int write(byte[] b,int nStart,int nLen) Kd`l[56#
{ +e\:C~2f28
int n = -1; <M=W)2D7
try{ zal3j^
oSavedFile.write(b,nStart,nLen); DMK"Q#Vw
n = nLen; \0*yxSg,^
} /\3XARt
catch(IOException e) `F-Dd4B
{ *FLTz(T
e.printStackTrace (); T,xVQ4J?
} fr,CH{Uq
6gg#Z
<750-d!
return n; <@x+N%C
} RBv=
$:-= >
#/XK&(X
} }'w^<:RSy
G8<It5CU
@0/@p"j
/* -+ IX[
**SiteInfoBean.java p@NEr,GB
*/ WrK^>
package NetFox; COkLn)+0
eLt Cxe
1CS]~1Yp:
public class SiteInfoBean { PTI'N%W
G5XnGl}Q
gKm~cjCB`~
private String sSiteURL; //Site's URL e u=f-HW]
private String sFilePath; //Saved File's Path 0\_R|i_`>
private String sFileName; //Saved File's Name ~qLhZR\g^
private int nSplitter; //Count of Splited Downloading File VtPoc(o4]
kGBl)0pr`x
PU@U@
public SiteInfoBean() i*cE
{//nSplitter的缺省值为5 AVevYbucB
//default value of nSplitter is 5 `X.=uG+m
this("","","",5); _>?8eC]4a
} `>Kk;`
"'H7F,k'
rfZj8R&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RQK**
{ whg4o|p
sSiteURL= sURL; bcx{_&1p
sFilePath = sPath; EH!EyNNb
sFileName = sName; =VX<eV
this.nSplitter = nSpiltter; @=zBF'<.9
}~\].I6
;uA_gn!
} 1Sc~Vb|>
`bt)'ERO%#
.+JPtL
public String getSSiteURL() e,j?_p
{ L&gEQDPgq|
return sSiteURL; k~9Ywf
} $qyM X[
>G3J3P(
7i|hlk;
public void setSSiteURL(String value) o}^vREO
{ I3E8vi%B.
sSiteURL = value; iDkWW
} ^J5V!i$
~3-YxCn%
oj4)7{
public String getSFilePath() }HQT@&=
{ ,IVr4#w0=
return sFilePath; +KwF U
} e[k;SSs
oWaIjU0
HS&uQc a
public void setSFilePath(String value) uF.\dY\xv
{ r0$9c
sFilePath = value; JU%yqXO
} v,.n/@s|X
1.d9{LO[-
"y ,(9_#
public String getSFileName() 7Hkf7\JY
{ Xi`U`7?D(=
return sFileName; [@FeRIu8
} 1oW]O@R
uA}FuOE6
?KuJs9SM
public void setSFileName(String value) Exs _LN
{ +MoxvW6
sFileName = value; +fQ$~vr{'
} O>):^$-K%
KZ >"L
tIy/QN_42
public int getNSplitter() 2mp>Mn~K^
{ bg3jo1J
return nSplitter; 7R`ZTfD
} 9kg>)ty@
Q@.9wEAJ
EV,NJ3V
public void setNSplitter(int nCount) yURh4@
{ c"&!=@
nSplitter = nCount; i.dAL)V
} e=Tc(Mwn
} Qc<O; #
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8}`8lOE7
/* _nFvM'`<
**Utility.java J1ro\"
*/ 1#_j6Q2
package NetFox; nz?BLO=
/Ta0}Y(y
3)MM5 bb$
public class Utility { 5OqsnL_V
j\L$dPZ
#w?%&,Kp
public Utility() z)y(31K<1
{ ph'SS=!.
a|{<#<6n(
pC.P
} `e;Sjf<
R/FV'qy]
//线程睡眠 Ytnr$*5.
public static void sleep(int nSecond) Us~wv"L=UX
{ QS?9&+JM|
try{ /%'7sx[p
Thread.sleep(nSecond); Y~?YA/.x
} |BWK"G
catch(Exception e) H9m2Whq
{ ?-v?SN#
e.printStackTrace (); @y2Bq['
} >oYwzK0&
} $[;eb,
=` >Nfa+,
//日志 F88SV6
public static void log(String sMsg) ~(P\F&A(&
{ >h-6B=
System.err.println(sMsg); .{ Lm
} Ps5wQaS
YZu#0)
#Z5Wk
public static void log(int sMsg) 3>3ZfFC
{ m`0{j1K
System.err.println(sMsg); EGO@`<"h
} tD482Sb=
} U,}T ]J
s/|'1E\F
dOgM9P
/* ptL}F~
**TestMethod.java (:k`wh&
*/ ]-OkW.8d1
package NetFox; =U|SK"oO
FOyfk$
BrmFwXLP"
public class TestMethod { xyCcd=
WZ-{K"56
Ybiz]1d
public TestMethod() A^7Zy79
{ ///xx/weblogic60b2_win.exe %cjav
try{ e%7P$.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z]_CFo1'l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZlXs7 &_
SiteFileFetch fileFetch = new SiteFileFetch(bean); {%}6d~Bg
fileFetch.start(); ~OfKn1D
} wWswuhq<
catch(Exception e){e.printStackTrace ();} O@&I.d$
Rzj!~`&N
{]N?DmF
} [NDYJ'VGe
G?(:Z=
r/:'}os;
public static void main(String[] args) @TG~fJSA12
{ )Em,3I/.l
new TestMethod(); o: DnZN
} #?|z&9
} 3{E}^ve
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