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)); C0N}B1-MU
} iSezrN
for(int i=0;i<nEndPos.length-1;i++) d;YKw1
{ Slg*[r#
nEndPos = nStartPos[i+1]; \^"Vqx
} F<g&t|@
nEndPos[nEndPos.length-1] = nFileLength; 6c-3+,Y"#
} ,4t6Cq!
} s0;a j<J
?# FYF\P
`i cs2po
//启动子线程 $Bz};@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XH~(=^/_
for(int i=0;i<nStartPos.length;i++) 4bA^Gq
{ /7#e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T^|k`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w=;>
nStartPos,nEndPos,i); "NLuAB.P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hq::F?
fileSplitterFetch.start(); .(q'7Q Z/
} dV38-IfGkl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HP]5"ziA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OS@uGp=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iZy>V$Aq
nEndPos = " + nFileLength); y4h =e~
// fileSplitterFetch[nPos.length-1].start(); $rcv@-l
"ymR8y'
5s3QN{h8
//等待子线程结束 4%~*}
//int count = 0; >4luZnWMI
//是否结束while循环 ;UTM9.o[
boolean breakWhile = false; Q&r.wV|
-fFtHw:kHh
C_Q3^mLx
while(!bStop) A_S7z*T
{ JH]S'5X8K
write_nPos(); 07:V[@'
Utility.sleep(500); ~M^[
breakWhile = true; L5x;#\#p
WyatHC
E8r6P:5d`
for(int i=0;i<nStartPos.length;i++) N Nk
{ *Igb3xK%
if(!fileSplitterFetch.bDownOver) )m;*d7l~p
{ JK<[]>O
breakWhile = false; 4RVqfD
break; jdJTOT
} 2kVZlt'y
} 8b'@_s!_
if(breakWhile) !38KHq^|&
break; UU>+b:
tNr'@ls
cdL]s^z
//count++; 5e,u*J]
//if(count>4) >eG<N@13p
// siteStop(); v2rO>NY4
} $aJ6i7C,j}
<{k{Coy
3f^Pr
System.err.println("文件下载结束！"); Vu.=,G
} vq(#Ih2
catch(Exception e){e.printStackTrace ();} L#K`F8Wi=
} vx($o9
&j1-Ouy
* rlVE
//获得文件长度 ZtO$kK%q;
public long getFileSize() 4xg)e` *U
{ pTq DPU
int nFileLength = -1; xAd@.^
try{ J/e]
URL url = new URL(siteInfoBean.getSSiteURL()); Wx]Xa]-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "!zJQl@
httpConnection.setRequestProperty("User-Agent","NetFox"); [yN+(^i
./XX
0ex.~S_Oj4
int responseCode=httpConnection.getResponseCode(); 1!(lpp
if(responseCode>=400) YOLzCnI4
{ H@@ 4n%MK
processErrorCode(responseCode); <9X@\uvU.<
return -2; //-2 represent access is error yR|2><A
} uFSU|SDd.
M]6+s`?r
\78^ O
String sHeader; _x(hlHFk
082iEG
bC:sd2s
for(int i=1;;i++) RKzty=j4
{ [pTdeg;QE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k)7i^1U
//Utility.log(in.readLine()); 7oF3^K'S
sHeader=httpConnection.getHeaderFieldKey(i); rmA?Xlh\
if(sHeader!=null) d*{Cv2A.
{ l,h`YIy
if(sHeader.equals("Content-Length")) W>a}g[Ad
{ }~zDcj_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )/'WboL
break; n-8/CBEH(
} %z@ Z^Jv
} N,qo/At}R[
else }_KzF~
break; }p6]az3
} o%~fJx:]y
} `.pEI q^
catch(IOException e){e.printStackTrace ();} a~jb%i_
catch(Exception e){e.printStackTrace ();} )M0(vog
Q/?`);
&v .S_Ym
Utility.log(nFileLength); L>IP!.J]?
w;ZT-Fti
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return nFileLength; BH {z]a
} I ==)a6^
'qT;Eht5
5&Yt=)c\
//保存下载信息（文件指针位置） zs]ubJC@
private void write_nPos() sc+%v1Y#}
{ J@/4CSCR]
try{ xwZ1Q,'C
output = new DataOutputStream(new FileOutputStream(tmpFile)); \0 h>!u
output.writeInt(nStartPos.length); 18NnXqe-m
for(int i=0;i<nStartPos.length;i++) ;6PU
{ VI4mEq,V
// output.writeLong(nPos); c>D~MCNxg
output.writeLong(fileSplitterFetch.nStartPos); u=InE|SH
output.writeLong(fileSplitterFetch.nEndPos); Jkj7ty.J
} kl:/PM^
output.close(); | CFG<]
} y%%VJ}'X!
catch(IOException e){e.printStackTrace ();} >gzM-d
catch(Exception e){e.printStackTrace ();} n(Nu
} :1qLRr
sG#Os
?1\I/'E9
//读取保存的下载信息（文件指针位置） wicsf<]
private void read_nPos() #Q7:Mu+
{ L^t%p1R
try{ .B~yI3D`M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m]U
int nCount = input.readInt(); KdozB!\
nStartPos = new long[nCount]; aPxSC>p
nEndPos = new long[nCount]; xwsl$Rj
for(int i=0;i<nStartPos.length;i++) agwbjkU/
{ vaF1e:(
nStartPos = input.readLong(); fpQFNV
nEndPos = input.readLong(); wT!?.Y)aj
} (v?@evQ
input.close(); E va&/o?P|
} aB~k8]q.
catch(IOException e){e.printStackTrace ();} m,+PYq
catch(Exception e){e.printStackTrace ();} 0o$RvxJ
} Y<W9LF
ktqFgU#rT
JmCHwyUK?
private void processErrorCode(int nErrorCode) 16Ka>=G
{ Fu{VO~w
System.err.println("Error Code : " + nErrorCode); $rj:K)P
} 2i6=g<
-'miM ~kG[
{'zS8
//停止文件下载 19GF%+L ,
public void siteStop() r&R~a9+)
{ )R `d x
bStop = true; UUWRC1EtI
for(int i=0;i<nStartPos.length;i++) >b\|%=(x!*
fileSplitterFetch.splitterStop(); v0) %S
0);5cbV7i
-<x%
} ,?m@Ko7Y
} YC%xW*
//负责部分文件的抓取 YvG$2F|_)
**FileSplitterFetch.java &J/!D#
*/ Y~*p27@fR
package NetFox; oO[eer_S-
Hz,Gn9:p
GtmoFSZ
import java.io.*; Y{j~;G@Wl
import java.net.*; `/m]K~~
g5 *E\T%8
dY$nw
public class FileSplitterFetch extends Thread { V#,|#2otZ
,Zie2I?q
*j83E[(]
String sURL; //File URL :1f,%Z$,q
long nStartPos; //File Snippet Start Position 4IZAJqw(*
long nEndPos; //File Snippet End Position _s#J\!F
int nThreadID; //Thread's ID WVQHb3Pe0
boolean bDownOver = false; //Downing is over 7n .A QII
boolean bStop = false; //Stop identical C\"C12n{
FileAccessI fileAccessI = null; //File Access interface %6fnL~A
n,2p)#?
:fRta[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nl2Lqu1
{ t5l<Lm)
this.sURL = sURL; #"A`:bjG
this.nStartPos = nStart; 5);"()g32
this.nEndPos = nEnd; .mrv"k\<
nThreadID = id; 1H">Rb30@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P2ySjgd
} u=@zYA(
]2"UR_x
#QlxEs#%
public void run() 6E_~8oEl
{ am5;B`}q
while(nStartPos < nEndPos && !bStop) R7:u 8-dU1
{ i885T'
&0*l:uw
^0_>
try{ p\~ a=
URL url = new URL(sURL); A#q.)8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lu>G=uCJ
httpConnection.setRequestProperty("User-Agent","NetFox"); s +S6'g--
String sProperty = "bytes="+nStartPos+"-"; W)Y-^i5
httpConnection.setRequestProperty("RANGE",sProperty); -+qg
Utility.log(sProperty); BuM#&]s
0*P-/)o x
FDiDHOR
InputStream input = httpConnection.getInputStream(); ,^ -%<
//logResponseHead(httpConnection); u$nmnd`g
pT+OPOSR
)qX.!&|I
byte[] b = new byte[1024]; lgt&kdc%o
int nRead; &9v8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !N\_D
{ yWc%z6dXC
nStartPos += fileAccessI.write(b,0,nRead); Pt-mLINvG
//if(nThreadID == 1) -k>k<bDAI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r.LOj6c
} CPsl/.$tC
nmL|v
-*&aE~Cs
Utility.log("Thread " + nThreadID + " is over!"); M4?>x[Pw
bDownOver = true; nRq[il0 `i
//nPos = fileAccessI.write (b,0,nRead); Xq"9TYf$
} V=1yg24B<
catch(Exception e){e.printStackTrace ();} Y -BZV |
} KvPLA{
} H^B,b!5i
xV`)?hEXFh
0:`YY8j1k
//打印回应的头信息 ~PpU'[
public void logResponseHead(HttpURLConnection con) !:vQg+S
{ b+AxTe("
for(int i=1;;i++) gi:M=
{ Eos;7$u[
String header=con.getHeaderFieldKey(i); iH>JR[A
if(header!=null) 8PeVHpZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g-x;a0MQx
Utility.log(header+" : "+con.getHeaderField(header)); 8j]QnH0&
else C2iOF/4
break; m=pH G
} RAEN &M
} &QHmo*
TgRG6?#^l
Ak`?,*LM
public void splitterStop() \8{Tj54NA
{ 2l+'p[b0>
bStop = true; 02^\np
} Zia6m[^Q
ex|)3|J
a(JtGjTf&
} y </i1qM
CpgaQG^
Ym]rG 4
/* !"08TCc<
**FileAccess.java guy!/zQ>A
*//文件访问(定位，写) @[/!e`]+
package NetFox; %<q"&]e,
import java.io.*; )5<dmK@
Vz5<Gr
:w4H$+j
public class FileAccessI implements Serializable{ ,:81DA
$Ixd;`l*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 da8 R.1o
RandomAccessFile oSavedFile; ~Ty6]A
long nPos; 4g.S!-H@R
%z @T /
"VsS-b^P
public FileAccessI() throws IOException HqOnZ>D
{ Oh}@c~7;
this("",0); T(qHi?Y
} (ke<^sv7!
Uzn
eLyIQoW
public FileAccessI(String sName,long nPos) throws IOException wDh&S{N
{ w6B`_Z'f
oSavedFile = new RandomAccessFile(sName,"rw"); iVqF]2>
this.nPos = nPos; Y k"yup@3
oSavedFile.seek(nPos); \\"CgH-
} .= 8Es#
!\&4,l(
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public synchronized int write(byte[] b,int nStart,int nLen) 3bugVJ93
{ )4+uM'2%
int n = -1; J2`OJsMwWe
try{ O_SM!!,
oSavedFile.write(b,nStart,nLen); SYOU&*
n = nLen; 8wS9%+
} f K4M:_u
catch(IOException e) WN#dR~>
{ Hp fTuydU
e.printStackTrace (); =0U"07%}
} |@ZyD$?
jm|zn
Rn whkb&&
return n; y+VRD
} k#@)gL
%bnjK#o"Q
;u%4K$
} 3'`X_C|d53
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NQvT4.*
/* 495(V(+5
**SiteInfoBean.java h"N#/zQ
*/ Qnp.Na[JV
package NetFox; piiO5fK|
_lk5\bu
|VoYFoiQ
public class SiteInfoBean { =u&NdMy
W!Rr_'yFe)
,Hsu;I~
private String sSiteURL; //Site's URL ~U4;YlQP
private String sFilePath; //Saved File's Path 0k|/]zfb
private String sFileName; //Saved File's Name *;(GL
private int nSplitter; //Count of Splited Downloading File v\COl*
xm<sH!,j
uFi[50
public SiteInfoBean() rg+3pX\{
{//nSplitter的缺省值为5 7o M]qLF
//default value of nSplitter is 5 :&D$Q 4
this("","","",5); o Bp.|8-
} 5s2/YG=
>5]w\^QN9_
"[]J[!}x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L2y{\<JC"
{ mZ t:
sSiteURL= sURL; C;!h4l7L
sFilePath = sPath; P~*v}A
sFileName = sName; <Xj ,>2m;
this.nSplitter = nSpiltter; AqP\g k
l_*:StyR+
X`n*M]
} g.O? 1bebe
cE]#23
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public String getSSiteURL() 04<T2)QgK
{ D61e
return sSiteURL; }=."X8zOI8
} jLf87
15~+Ga4
r;aP`MVO<
public void setSSiteURL(String value) &@xeWB
{ vui{["
sSiteURL = value; wZUR
} 3H47 vm(`
[ w1"
\8X8NCM
public String getSFilePath() (vf5qF^
{ 1]XIF?_Dm
return sFilePath; j2|!h%{nI
} -`ykVHgg
*C?x\.\C
V.274e
public void setSFilePath(String value) 5Bc)QKh`l|
{ =!Y{Mz
sFilePath = value; /%GMbO_
} N[,/VCW
pV))g e\
4.mbW
public String getSFileName() C(*)7| m
{ A,s .<TG
return sFileName; tlFc+3
} IsCJdgG
9^c"HyR
{VE$i2nC8
public void setSFileName(String value) 8m"5J-uIi
{ P%Ux-0&
sFileName = value; *8CE0;p'k
} Q,`Y
6.'+y1yS)
|]H2a;vUJR
public int getNSplitter() Wh>Y_ k
{ 9qQFIw~S
return nSplitter; @V-CG!
} &_E*]Sj\
#0WO~wL
cBA2;5E
public void setNSplitter(int nCount) [}_ar
{ ZvO:!u0+"
nSplitter = nCount; uQ.VW/>
} BPd]L=,/
} MY[" zv
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#B)`dA0a
/* tgYIM`f
**Utility.java 93(
*/ O_PC/=m1@
package NetFox; $mOK|=tI_
g%<7Px[W
{:enoV"
public class Utility { 6A/|XwfE/v
K~WwV8c9;
Ja#idF[V
public Utility() Z [5HI;
{ fwQ%mU+
)V}u1C-N
#UJ@P Dwil
} Ve8`5
[P{Xg:0
//线程睡眠 4"j5@bppJ
public static void sleep(int nSecond) 8`qw1dF
{ ()>\D
try{ EX&y !
Thread.sleep(nSecond); rd1&?X
} o#wF/ I
catch(Exception e) I$wP`gQh
{ _bks*.9}3b
e.printStackTrace (); Gf'V68,l$
} xI~\15PhG
} =4MiV]
FM7N|] m
//日志 "=f*Lk@[
public static void log(String sMsg) D_9/|:N:
{ M=N`&m\
System.err.println(sMsg); t@v>eb
} 4!gyFi6$
W#y)ukRv
xD1B50y U
public static void log(int sMsg) IW1]H~1w
{ ,?#-1uIGL>
System.err.println(sMsg); w-CuO4P
} ,_lwT}*w
} @3S2Xb{ra1
"ej>1{3Y:=
uR)@v^$FE
/* ]-fZeyY$
**TestMethod.java V`WfJ>{;Z
*/ y~S[0]y>
package NetFox; ypd
up2%QbN(
^LC5orO
public class TestMethod { 6y5arP*6e
{2:H`|x
%r!#
public TestMethod() H[Pb Wy:
{ ///xx/weblogic60b2_win.exe puqH%m+u
try{ >LU*F|F]B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KuI>:i;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yMSRUQ x
SiteFileFetch fileFetch = new SiteFileFetch(bean); Iwn@%?7
fileFetch.start(); W'0wTZG
} oC[wYUDg
catch(Exception e){e.printStackTrace ();} Yu1xJgl
:6M0`V;L
{G{@bUG]p
} @i)tQd!s
sy@k3wQ
bo -Gh`
public static void main(String[] args) x)*/3[
{ vp_$6
new TestMethod(); [X~X?By>
} 7e=a D~f
} \qTn"1bQ
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