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)); f#38QP-T
} c[6<UkH7
for(int i=0;i<nEndPos.length-1;i++) 9nd,8Nji
{ !y1qd
nEndPos = nStartPos[i+1]; 6[Mu3.T
} BMzS3;1_
nEndPos[nEndPos.length-1] = nFileLength; |Ntretz`\
} 9D5v0Qi
} fob.?ID-;
*[3tGiUJ
yBqKldl
//启动子线程 IjPtJwW`A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;k1VY Ie}
for(int i=0;i<nStartPos.length;i++) V[*<^%
{ i:R_g]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #FGj)pu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sVS),9\}
nStartPos,nEndPos,i); E_xCRfw_i]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zM%2h:*+{
fileSplitterFetch.start(); GQ9H>Ssz
} }1Hy[4B(k\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I&&[ ':
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,Igd<A=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *kGk.a=
nEndPos = " + nFileLength); p ^I#9(PT
// fileSplitterFetch[nPos.length-1].start(); (ap,3$hS
0@jhNtL
G/Yqvu,2!
//等待子线程结束 }(UU~V
//int count = 0; ibuoq X`
//是否结束while循环 H3|x
boolean breakWhile = false; V(!-xu1,
8Vm)jnM
`Yo!sgPO\
while(!bStop) ftqeiZ 2
{ JW=P}h
write_nPos(); JN<u4\e{-&
Utility.sleep(500); ^1+=HdN,
breakWhile = true; x)2ZbIDB:"
WaDdZIz4
K1|xatx1V
for(int i=0;i<nStartPos.length;i++) ARJ}h
{ RATW[(ZA
if(!fileSplitterFetch.bDownOver) Z'\{hL S
{ II}3w#r4
breakWhile = false; w;DRC5V>
break; tq8rG@-C
} ;fKFmY41
} ,=t}|!jx
if(breakWhile) gY!#=?/S
break; !Im{-t
p>0n~e
,mvU`>Ry
//count++; {wVJv1*l
//if(count>4) ^yVKW5x
// siteStop(); $n9Bp'<
} Z/[ww8b.
P4dhP-t
&-M}:'
System.err.println("文件下载结束！"); }>~]q)]
} ^q)s
catch(Exception e){e.printStackTrace ();} ^@n?&
} &0%x6vea
EPGp8VGXp~
?LA`v_
//获得文件长度 =S}SZYwl
public long getFileSize() uO}UvMW
{ H.]rH,8
int nFileLength = -1; G[z4 $0f
try{ QwgP+ M+
URL url = new URL(siteInfoBean.getSSiteURL()); 2<8JY4]!]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3=xN)j#B
httpConnection.setRequestProperty("User-Agent","NetFox"); t7qY!S (
+{pS2I}d
a+ lGN
int responseCode=httpConnection.getResponseCode(); =^S1+B MY-
if(responseCode>=400) iF'qaqHWY4
{ $@Kwsoh'
processErrorCode(responseCode); "YePd*W
return -2; //-2 represent access is error UbSAyf
} eg Zb)pP
}D\i1/Y
k86j& .m_
String sHeader; l#k&&rI5x.
P\2UIAPa\b
nH7i)!cI~
for(int i=1;;i++) AI\|8[kf0
{ @eU5b63jM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TW5Pt{X=f
//Utility.log(in.readLine()); ?kKr/f4N
sHeader=httpConnection.getHeaderFieldKey(i); ym.:I@b?6
if(sHeader!=null) Q% LQP!Kg
{ p`2w\P3;)
if(sHeader.equals("Content-Length")) $~FnBD%|{
{ =9y&j-F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); voJmNH
break; n/jZi54gO
} 5T- N\)@
} c6_i~0W56
else 2{fPQQ;#
break; T?Y/0znB*
} .`Rju|l
} T.x"a$AU
catch(IOException e){e.printStackTrace ();} ?'I pR
catch(Exception e){e.printStackTrace ();} N!iugGL
"D1u2>(
\4 5%K|
Utility.log(nFileLength); 9E-]S'Z
}Z Nyd
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return nFileLength; AIX?840V
} pRrokYM d
>hsvRX\_`
(f `zd.
//保存下载信息（文件指针位置） E\lel4ai
private void write_nPos() w:+wx/\
{ 5w#7B
try{ 6h%_\I.Z[[
output = new DataOutputStream(new FileOutputStream(tmpFile)); K! I]0!:
output.writeInt(nStartPos.length); #9FY;~
for(int i=0;i<nStartPos.length;i++) g;To}0H
{ ZtPnHs.x
// output.writeLong(nPos); |];f?1
output.writeLong(fileSplitterFetch.nStartPos); Vnvfu!>(
output.writeLong(fileSplitterFetch.nEndPos); :7Jpt3
} LCouDk(=`
output.close(); ll8Zo+-[
} ~H1ZQ[
catch(IOException e){e.printStackTrace ();} K 0Gm ?(
catch(Exception e){e.printStackTrace ();} ~us1Df0bp
} i}E&mv'
ngI3.v/R
6#za\[
//读取保存的下载信息（文件指针位置） |(77ao3
private void read_nPos() {Ne5*HFV
{ Z0#&D&2sV
try{ FBGe s[,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pg\!\5
int nCount = input.readInt(); UZJ<|[
nStartPos = new long[nCount]; jhF&
nEndPos = new long[nCount]; %(YU*Tf~
for(int i=0;i<nStartPos.length;i++) wJMk%N~R:
{ Um2RLM%
nStartPos = input.readLong(); XSoHh-
nEndPos = input.readLong(); /*kc|V
} V''?kVJ
input.close(); U *K6FWqiB
} qayM0i>>
catch(IOException e){e.printStackTrace ();} J_`a}ox
catch(Exception e){e.printStackTrace ();} u/ZV35z
} >O$JS,
PL|zm5923
3)0z(30
private void processErrorCode(int nErrorCode) rm?C_
{ ?(R!BB
System.err.println("Error Code : " + nErrorCode); )1, U~+JFU
} H9%[! RF
[M/0Qx[,
v9"|VhZ
//停止文件下载 57(5+Zme
public void siteStop() dKJ-{LV
{ p>9|JMk
bStop = true; [!ilcHE)
for(int i=0;i<nStartPos.length;i++) h-+vNhH
fileSplitterFetch.splitterStop(); Ou7nk:I@
aE 2=
^d@ME<mb
} U uEm{
} FFq8LM8
//负责部分文件的抓取 SbXV'&M2AT
**FileSplitterFetch.java 9 .18E(-
*/ &N.]8x5A
package NetFox; -^ R?O
)K!!Zq3;|
w\lc;4U
import java.io.*; \N[2-;[3
import java.net.*; l8H8c &
+%=lu14G
MWq1 "c
public class FileSplitterFetch extends Thread { ":!1gC
;Z.sK-NJ4
p)Fi{%bc
String sURL; //File URL J;*2[o.N
long nStartPos; //File Snippet Start Position Mb:>
long nEndPos; //File Snippet End Position jp880}
int nThreadID; //Thread's ID Rrw6\iO
boolean bDownOver = false; //Downing is over J b?x-%Za
boolean bStop = false; //Stop identical &t,"k'p
FileAccessI fileAccessI = null; //File Access interface b ,e"x48q
~xt]g zp{
S{jm4LZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;Iax \rQ
{ .2V?G]u
this.sURL = sURL; ? J/NYV
this.nStartPos = nStart; ok1-`c P
this.nEndPos = nEnd; oS^g "hQ`\
nThreadID = id; GJIZu&C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q+2v9K@
} BG_6$9y
N<~LgH
6%Pvh- ~_
public void run() kgP6'`}E[
{ U8OVn(qV
while(nStartPos < nEndPos && !bStop) $CDRIn50
{ _[h!r;DsG
*:?XbtIK u
s0m k<>z
try{ /HVxZ2bar
URL url = new URL(sURL); dlH&8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N{H#j6QW
httpConnection.setRequestProperty("User-Agent","NetFox"); #_Z)2ESX
String sProperty = "bytes="+nStartPos+"-"; 8Om4G]*|,
httpConnection.setRequestProperty("RANGE",sProperty); XwIhD
Utility.log(sProperty); PckAL
R>hL.+l.
k>F>y|m
InputStream input = httpConnection.getInputStream(); \3T[Cy|5|
//logResponseHead(httpConnection); d>O/Zal
PQ2rNY6
a y$CUw
byte[] b = new byte[1024]; pfQ3Y$z
int nRead; YBL.R;^v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w1LZ\nA<
{ g>QN9v})
nStartPos += fileAccessI.write(b,0,nRead); ',!>9Dj
//if(nThreadID == 1) r0s(MyI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {hoe^07XK
} 4+:'$Nw
e"|ZTg+U
i,2eoM)FB
Utility.log("Thread " + nThreadID + " is over!"); 3LZvlcLb
bDownOver = true; mhI
//nPos = fileAccessI.write (b,0,nRead); {7Hc00FM
} 7c83g2|%
catch(Exception e){e.printStackTrace ();} d%:J-UtG"
} eq@-J+
} `SQobH
vr4{|5M
CYYo+5x
//打印回应的头信息 O-ppR7edh
public void logResponseHead(HttpURLConnection con) oG\lejO
{ <B!DwMk;.
for(int i=1;;i++) NH4T*R)Vz
{ U6#9W}CE
String header=con.getHeaderFieldKey(i); %WPyc%I
if(header!=null) ;Kh?iqn^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qfqL"G
Utility.log(header+" : "+con.getHeaderField(header)); 8x-(7[#e<g
else j!"5,~
break; ~9#'s'
} q4g)/x%nc
} K%UjPzPWw
XB]>Z)
o|w w>m
public void splitterStop() Q]<6voyy
{ @U:PXCvh
bStop = true; |CAMdU
} !Y 9V1oVf"
_<'?s>(U'
Ymf@r?F<
} K5F;/KR"
^ywDa^;-
uSv]1m_-]
/* H.[nr:
**FileAccess.java %<`sDO6Q?
*//文件访问(定位，写) >J#/IjCW
package NetFox; P 1
import java.io.*; ^91Ae!)d
na@Go@q
)Myx(w"S
public class FileAccessI implements Serializable{ HX ,\a`
ZC`VuCg2O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iNilk!d6Q3
RandomAccessFile oSavedFile; ;]k\F
long nPos; (gIFuOGi>
;*hVAxs1
jhJ<JDJ?`
public FileAccessI() throws IOException '(-H#D.oy'
{ ez~u A4
this("",0); IaKJ W?
} s1tkiX{>
1jE {]/Y7&
y;_F[m
public FileAccessI(String sName,long nPos) throws IOException 5s@xpWVot
{ sRZ?Ilua6
oSavedFile = new RandomAccessFile(sName,"rw"); 5n1`$T.WG
this.nPos = nPos; ={51fr/C%
oSavedFile.seek(nPos); 6 X'#F,M
} "{kE#`c6<n
"{Hl! Zq/
pu_?)U
public synchronized int write(byte[] b,int nStart,int nLen) ]x(6^:D5
{ Dl,sl>{
int n = -1; Sjo-Xf}
try{ Ibx\k
oSavedFile.write(b,nStart,nLen); S(/^_Y
n = nLen; ^Vf@J
} a^_W}gzzd
catch(IOException e) wc-v]$DW
{ Ai)>ot
e.printStackTrace (); (EjlnG}5l
} Z?'?|vM
,/kZt!
nw#AKtd@x
return n; Nw(hN+_u
} Qg0%rbE
(" +clb`
=uEpeL~d;+
} 2vhP'?;K
HD3WsIim*
?H>^X)Ph
/* H[}lzL)
**SiteInfoBean.java ouO9%)zv
*/ &PMfAo^
package NetFox; 0/1=2E^,
%gj7KF
[WV&Y,E
public class SiteInfoBean { f>e0l'\
/qMiv7m~Q
`jyyRwSoe
private String sSiteURL; //Site's URL a8-V`
private String sFilePath; //Saved File's Path O*Y?: t
private String sFileName; //Saved File's Name ].2t7{64
private int nSplitter; //Count of Splited Downloading File :4\%a4{Ie
";7/8(LBZ
f=.!/e70
public SiteInfoBean() (F9e.QyWb
{//nSplitter的缺省值为5 D!ASO]
//default value of nSplitter is 5 BoOuN94
this("","","",5); u~>G8y)k9O
} gXU(0(Gq
|Y?<58[!)
q8n@fi6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y#8 W1%{x
{ i`W~-J
sSiteURL= sURL; QcJC:sP\>
sFilePath = sPath; mU"Am0Bdjq
sFileName = sName; Y[_|sIy*
this.nSplitter = nSpiltter; 'X6Z:dZY
_1mpsY<k
X|G[Ma?
} 2-jXj9kp`
f~/hsp~Hp
!"&-k:|g
public String getSSiteURL() bC98<if
{ =qpGAv_#
return sSiteURL; k+*pg4'
} f=VlOd
6 EfBz
:RxMZwa=
public void setSSiteURL(String value) iX<" \pV
{ wwQ2\2w>Hm
sSiteURL = value; H=w):kL|
} vVIND
J*Ie# :J]
+6$-"lf
public String getSFilePath() (:O6sTx-hE
{ <&gs)BY
return sFilePath; T>7N "C
} m{$}u@a
<QC7HR
uPapINj
public void setSFilePath(String value) sINf/mv+
{ LI&E.(:
sFilePath = value; 3 S*KjY'@
} *SIYZE'
Vh2uzG
>B=s+}/ME
public String getSFileName() 7l[@c|e
{ i$`o,m#
return sFileName; 12?!Z
} r:$*pC&{
m#i4_F=^b
e|5@7~Vi
public void setSFileName(String value) |yz o|%]3
{ -iY-rzW
sFileName = value; `#wEa'v6
} f F)M'C
S=.%aB
V5i}^%QSs
public int getNSplitter() kFY2VPP~
{ ?1c7wEk
return nSplitter; ;(J&%
} '/t9#I@G\
.'Q*_};W
HY1K(T
public void setNSplitter(int nCount) Nnr[@^M5
{ "Nb2[R
nSplitter = nCount; Y .cjEeL@
} 6 C O5:\
} Q4L=]qc T
B$YoglEW:
-mGG:#yP
/* 'DNxc
**Utility.java IVZUB*wv)b
*/ @$ Nti>
package NetFox; <66%(J>
(aC=,5N
j|`lOH8
public class Utility { 7SH3k=x
&-p~UZy
;%(sbA
public Utility() HRrR"b9:
{ FG+pR8aA$
,c$tKj5ulQ
ujkWVE'
} (*=>YE'V{
g6aqsa
//线程睡眠 /W-ges
public static void sleep(int nSecond) S[yrGX8lu
{ VpAwvMw
try{ @mv G=:k
Thread.sleep(nSecond); kksffzG
} Ejr'Yzl3_
catch(Exception e) /kK!xe
{ q~5zv4NX
e.printStackTrace (); | 4}Y:d
} %4F\#" A
} \`["IkSg7
hmOGteAf-
//日志 J Eo;Fx]
public static void log(String sMsg) vnVT0)Lel
{ 4 qY
System.err.println(sMsg); !G\gqkSL
} zLJmHb{(
Zi7cp6~7
NqD Hrx
public static void log(int sMsg) zv0sz])
{ ~@PD\
System.err.println(sMsg); [7HBn
} Vy[xu$y
} (ER9.k2
Wa.xm_4s2
>B~? }@^Gk
/* 53ZbtEwhwr
**TestMethod.java <82&F
*/ +WR?<*_
package NetFox; oQ/T5cOj
oIx|)[
(~{Y}n]s
public class TestMethod { Vp~ cN
6| o S 5
@RszPH1B
public TestMethod() H25Qx;(dTk
{ ///xx/weblogic60b2_win.exe CueC![pj
try{ Sy1O;RTn`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |[mmEYc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <%%)C>l
SiteFileFetch fileFetch = new SiteFileFetch(bean); Qk>U=]U
fileFetch.start(); !X$19"
} Xx[,n-rA
catch(Exception e){e.printStackTrace ();} }2e s"
cuumQQ
*c=vEQn-
} f(blqO.@l
u^|cG{i5"
<)~-]
public static void main(String[] args) U9^1A*
{ @R%qP>_
new TestMethod(); 0%[IG$u)|
} kh=<M{-t
} p4k}B. f
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