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)); vrH/Z.WD
} :Vv=p*~
for(int i=0;i<nEndPos.length-1;i++) <CeDIX t
{ aaLT%
nEndPos = nStartPos[i+1]; hEDj"`Px
} 7Ij'!@no
nEndPos[nEndPos.length-1] = nFileLength; 9Czc$fSSt
} Ur_~yX]Mo
} cBU>/ zIp
F$d`Umqs;P
0rF{"HM~
//启动子线程 x6m21DWw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /KH3v!G0
for(int i=0;i<nStartPos.length;i++) syMB~g
{ 9kTU|py
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !}U&%2<69
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Fe8xOo6
nStartPos,nEndPos,i); H$Q_K<V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !uHX2B+~
fileSplitterFetch.start(); &Jq?tnNd
} oveW)~4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7GpSWM6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o: qB#8X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \T>f+0=4
nEndPos = " + nFileLength); \!`*F:7]-
// fileSplitterFetch[nPos.length-1].start(); gJ:Z7b
XBCz\f
\ 3ha
//等待子线程结束 xCGvLvFn
//int count = 0; k}~|jLu@g
//是否结束while循环 st~f}w@
boolean breakWhile = false; 7R ;!
H;|^z@RB<
D.X%wJ8
while(!bStop) O]`CSTv'_
{ fZ$8PMZv
write_nPos(); F8.Fp[_tM
Utility.sleep(500); Sa6}xe."M,
breakWhile = true; jrG@ +" }
2UA h^i-^
"|(+~8[
for(int i=0;i<nStartPos.length;i++) n hS=t8H
{ ur"ckuG!9
if(!fileSplitterFetch.bDownOver) d.sxB}_O
{ njX!Ez
breakWhile = false; 6*Rz}RQ
break; LC2t,!RRl&
} YEQ}<\B\&
} [ q22?kT
if(breakWhile) PO1sVP.S
break; 8nW#Q<s
}3ty2D#/:
MX]<tR`
//count++; u9_ Fjm}&
//if(count>4) UJ2Tj+
// siteStop(); g#W)EXUR
} v~9PS2
>}Za)
*ix&"|h
System.err.println("文件下载结束！"); Bzw~OB{!=J
} xbSix:R=Z
catch(Exception e){e.printStackTrace ();} PohG y
} ?=$a6o
,_D`0B6o
Y 8EL
//获得文件长度 8N'[)Jw
public long getFileSize() n'K,*
{ 3t)07(x_B
int nFileLength = -1; twq!@C
try{ \IQf|
URL url = new URL(siteInfoBean.getSSiteURL()); %[l5){:05
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b[%sKl
httpConnection.setRequestProperty("User-Agent","NetFox"); +' QX`
ez@`&cJ7
)\8l6Gw
int responseCode=httpConnection.getResponseCode(); Dqs{n?@n
if(responseCode>=400) $_onSYWr
{ ~K5eO-
processErrorCode(responseCode); X3P~z8_
return -2; //-2 represent access is error 4 bw8^
} !"Jne'f
Ivmiz{Oii
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String sHeader; .i) H1sD
*0^!%Y'/4
T8bk\\Od
for(int i=1;;i++) 1kEXTs=,
{ IVjH.BzH9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9@9(zUS|
//Utility.log(in.readLine()); ,6uON@
sHeader=httpConnection.getHeaderFieldKey(i); |#^wYZO1U
if(sHeader!=null) iimTr_TEt
{ @FKm_q
if(sHeader.equals("Content-Length")) E3@G^Y
{ 4V@raI-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n6Je5fE
break; i 3?=up!
} dkVF
} dDK4I3a
else W2?6f:
break; jdqVS@SD
} JR] /\(
} *](maF~%C
catch(IOException e){e.printStackTrace ();} hd^?mZ
catch(Exception e){e.printStackTrace ();} x1VBO.t=*
>x]b"@Hkw
c6.S jV
Utility.log(nFileLength); (NR8B9qLN
">_<L.,I
% P .(L
return nFileLength; @ qy n[C
} SaceIV%(
ux`)jOQ`Y]
<&^P1x<x
//保存下载信息（文件指针位置） 6O"?wN%$
private void write_nPos() |Ii[WfFA|J
{ R9@Dd
try{ E%8Op{zv_
output = new DataOutputStream(new FileOutputStream(tmpFile)); :Aj8u\3!@
output.writeInt(nStartPos.length); GrPKJ~{6
for(int i=0;i<nStartPos.length;i++) t.Q}V5t{g
{ {RcmjI7
// output.writeLong(nPos); K9O%SfshF
output.writeLong(fileSplitterFetch.nStartPos); xVw9_il2a
output.writeLong(fileSplitterFetch.nEndPos); }-jS0{i
} [CxnGeKK
output.close(); DLggR3K_\
} . 7*k}@k
catch(IOException e){e.printStackTrace ();} .,[NJ:l
catch(Exception e){e.printStackTrace ();} g^ .g9"
} @`t#Bi9
H2[VZ&Pg
7~&
//读取保存的下载信息（文件指针位置） tQ~vLPi$
private void read_nPos() goBl~fqy0
{ w{TZN{Y
try{ @pq2Z^SQH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $1lI6 = ,
int nCount = input.readInt(); 9n9Z
nStartPos = new long[nCount]; l ld,&N8
nEndPos = new long[nCount]; ggn C #$
for(int i=0;i<nStartPos.length;i++) >1uo5,wrF
{ [.:SV|AF#
nStartPos = input.readLong(); XK#~w:/fB
nEndPos = input.readLong(); E/+H~YzO
} T1$=0VSEa+
input.close(); B\^myg4
} st4z+$L
catch(IOException e){e.printStackTrace ();} 8k[=$Ro
catch(Exception e){e.printStackTrace ();} 8[v9|r
} y950Q%B]
{o>51fXc)
b^s978qn#
private void processErrorCode(int nErrorCode) >I*)0tE
{ @G'&7-(h*
System.err.println("Error Code : " + nErrorCode); zP554Gr?
} oW ! Z=;
n$Nb,/o
9d kuvk}:
//停止文件下载 n0)0"S|y1
public void siteStop() S:5vC{
{ Odn`q=
bStop = true; )T0%<(J
for(int i=0;i<nStartPos.length;i++) r{LrQ
fileSplitterFetch.splitterStop(); }`fFzb
?`T0zpC
|)5xmN]
} Z01BzIsR
} oyw*Z_9~
//负责部分文件的抓取 a%nksuP3
**FileSplitterFetch.java =:fN
*/ 0+3_CS++r
package NetFox; >;qAj!'
=1ltX+
}^Ymg7wA
import java.io.*; G.{)#cR
import java.net.*; qe/dWJBa
1Jm'9iy3
yj$a0Rgkv
public class FileSplitterFetch extends Thread { 2eC`^
t@(:S6d
t_xO-fT)
String sURL; //File URL b?^CnMO
long nStartPos; //File Snippet Start Position U~CG(9
long nEndPos; //File Snippet End Position ]9A@iA
int nThreadID; //Thread's ID DjLSl,Z
boolean bDownOver = false; //Downing is over xVnk]:c
boolean bStop = false; //Stop identical ;15j\{r
FileAccessI fileAccessI = null; //File Access interface ]#NJ[IZb
%>io$o
npCiqO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^WF/gup\hS
{ Q$bi:EyJXc
this.sURL = sURL; I@/s&$H`l
this.nStartPos = nStart; Sgp1p}
this.nEndPos = nEnd; hnYL<<AA
nThreadID = id; r'F)8%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C}'Tmi
} {D{' \]+
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public void run() WY& [%r
{ V|\dnVQ'-%
while(nStartPos < nEndPos && !bStop) #r,LV}*qg
{ |YnT;q
pLiGky
8pXului
try{ 9cqq"-$G`
URL url = new URL(sURL); 2%Mgg,/~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $-w&<U$E
httpConnection.setRequestProperty("User-Agent","NetFox"); "7z1V{ ;Y
String sProperty = "bytes="+nStartPos+"-"; 0Z4o3r[
httpConnection.setRequestProperty("RANGE",sProperty); w;p~|!
Utility.log(sProperty); uN;]Fv@Z
Ss~yy0
P->.eo#VG
InputStream input = httpConnection.getInputStream(); hU|TP3*
//logResponseHead(httpConnection); gm8FmjZtf
eAl;:0=%L
rYI7V?
byte[] b = new byte[1024]; Z1dLC'/b]
int nRead; VN/v]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }!_ofe
{ wZnv*t_
nStartPos += fileAccessI.write(b,0,nRead); bXNM.K
//if(nThreadID == 1) #S|DoeFs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6%A_PP3Z
} X,mqQ7+
4:0y\M5u
Vh}F#~BrI
Utility.log("Thread " + nThreadID + " is over!"); SJ8CBxA
bDownOver = true; HU1ZQkf
//nPos = fileAccessI.write (b,0,nRead); bu:%"l
} `JAM]qB"
catch(Exception e){e.printStackTrace ();} zL@FN sYVM
} "i^< H
} `^mY*Cb e
BM>'w,$KL
.|g|X8X
//打印回应的头信息 TbQ5
public void logResponseHead(HttpURLConnection con) Y;"rJxHD
{ MJ_]N+
for(int i=1;;i++) )|N_Q}
{ V`& O`
String header=con.getHeaderFieldKey(i); i"RBk%
if(header!=null) g4f:K=5:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o,gH*
Utility.log(header+" : "+con.getHeaderField(header)); e.'6q ($3
else !mIr_d2"
break; 7^FJ+gN8b
} !v\_<8
} ),rd7GB>
RQO&F$R=
ZcE:r+
public void splitterStop() &cf(}
{ +i@{h9"6g
bStop = true; I-L:;~.
} 0nsjihw
iOrpr,@
`Kb"`}`_vm
} ] ^s,
:cA%lKg
,SG-{
/* \'hZm%S
**FileAccess.java !XQq*
*//文件访问(定位，写) L/KiE+Y
package NetFox; |PxTm
import java.io.*; fq<JX5DER
~]V}wZt>h
chakp!S=
public class FileAccessI implements Serializable{ Vk:] aveW
.8dlf7* ,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "pMx(
RandomAccessFile oSavedFile; hF^y4v|5
long nPos; 13aj fH
LQz6op}R
fWs@ZCt
public FileAccessI() throws IOException 'Da*MGu9
{ w#^z:7fI
this("",0); !4mg]~G
} <! Z06
%3Tz%>n
;"w?@ELE
public FileAccessI(String sName,long nPos) throws IOException vhd+A
{ B>UF dj]-
oSavedFile = new RandomAccessFile(sName,"rw"); L+D9ZE]
this.nPos = nPos; b <z)4
oSavedFile.seek(nPos); h/pm$9A
} C @nA*
I%M"I0FV
GV0-"9uwX~
public synchronized int write(byte[] b,int nStart,int nLen) z(eAhK}6?
{ T)o>U&KNP
int n = -1; ]114\JE
try{ !g7lJ\B
oSavedFile.write(b,nStart,nLen); 1LVO0lT
n = nLen; {$QkerW3
} ~-f"&@){,
catch(IOException e) -*[:3%
{ _lMSW6
e.printStackTrace (); D~b_nFD
} ;Q>+#5H6F8
czg9tG8
v%@)I_6[P
return n; KdXqW0nm
} wV^c@.ga
?np3*;lw
0vZ49}mb)
} v2jpao<K
pD17r}%
6wq>&P5
/* .R]DT5
**SiteInfoBean.java gP.PyYUV
*/ Yfr4<;%
package NetFox; b_Dd$NC
B'&QLO|
W2BZG(dm
public class SiteInfoBean { H>]A|-rG#
b?K`DUju{0
Ctx`b[&KXX
private String sSiteURL; //Site's URL 5@_kGoqd
private String sFilePath; //Saved File's Path '.{_ 7U
private String sFileName; //Saved File's Name }fJLY\
private int nSplitter; //Count of Splited Downloading File #Q1}h
):lH
26ae|2?
public SiteInfoBean() lWakyCS
{//nSplitter的缺省值为5 LYO2L1u)
//default value of nSplitter is 5 bm poptfL
this("","","",5); {s>V'+H(F
} M(?0c}z
k`w/
dJ{q}U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :i>If:>g
{ $38)_{
sSiteURL= sURL; [\e/xY(4
sFilePath = sPath; .Ta(v3om%
sFileName = sName; H/y,}z
this.nSplitter = nSpiltter; .: k6Kg
_tRRIW"Vx"
<Hr~|oG
} 8n35lI( [
&grqRt
o Vpq*"
public String getSSiteURL() VWc)AfKe
{ #$ 4g&8
return sSiteURL; 3EHB~rL/C
} :DrF)1C
zGNmc7
K /$-H#;N
public void setSSiteURL(String value) <$u\PJF7_^
{ i1ScXKO
sSiteURL = value; [1nUq!uTm
} Mc&Fj1h5
J7Mbv2D
IN75zn*%
public String getSFilePath() Tje(hnN
{ -3u ;U,}
return sFilePath; <eZ*LK?
} [HI$[:[
U!(es0rX
_2Mpzv
public void setSFilePath(String value) U C_$5~8p
{ GvZ[3GT
sFilePath = value; {isL<
} adPd}rt;
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( k,?)
public String getSFileName() zdm2`D;~p
{ e/&^~ $h
return sFileName; E\ls- (,
} 3m| C8:
THARr#1b};
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public void setSFileName(String value) mVFo2^%v
{ BOWBD@y
sFileName = value; u 7:Iv
} A"z9t#dv@
74 &q2g{
+D2I~hC0'
public int getNSplitter() W>5[_d
{ _M+7)[xj=
return nSplitter; s94*uZ(C/
} 0*_E'0L8e
,OERDWW|6
|Sm/s;&c6
public void setNSplitter(int nCount) ]6F\a= J
{ u-_1)'
nSplitter = nCount; - AU{Y`j
} u HW'F(;
} Mo5b @ [
}m'n1tm;
f!{@{\
/* oKCv$>Y
**Utility.java :_tt9J
*/ uXk]
package NetFox; w {"1V7|
jwUX?`6jX
I _gE`N
public class Utility { >ZW|wpO
Z/dhp0k
4Us_Z{.
public Utility() uuxVVgWp{
{ qXhdU/ =
Y%eq2%
R8_I ASs
} 'y=N_/+s
GGf<9!:
//线程睡眠 Le:(;:eL>t
public static void sleep(int nSecond) h[&"KA
{ `<7!Rh,tS^
try{ ]Axz}:
Thread.sleep(nSecond); EY:IwDA.}
} *AYq:n6
catch(Exception e) ""Da2Md
{ '_^T]fr}
e.printStackTrace (); z:@:B:E
} {}$Zff
} 0|J_'-<
7}g4ePYag
//日志 dI&Q5M8
public static void log(String sMsg) TL)*onA9
{ (0B?OkQ
System.err.println(sMsg); g`%in
} cPD_=.&
&w#!
c!_c, vwrn
public static void log(int sMsg) ?C#E_
{ ~MBPN4r
System.err.println(sMsg); #c5jCy}n
} N+h05`
} l?=\9y
D}q"^"#T
"4;nnq
/* 8!rdqI
**TestMethod.java -(t7>s
*/ pF4Z4?W
package NetFox; =E5bM_P<K
__2<v?\
P RWb6
public class TestMethod { Qr9;CVW
?oFd%|I
fT|A^
public TestMethod() ,/D}a3JD
{ ///xx/weblogic60b2_win.exe Z*q9vX
try{ gf1+yJ^d!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i=cST8!8N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KWZhCS?[(
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3iIy_nWC
fileFetch.start(); qh:Bc$S
} aPVzOBp
catch(Exception e){e.printStackTrace ();} |Ha#2pt{bc
vWZXb`
=29IHL3
} MDU#V
?%h$deJ
ca{MJz'
public static void main(String[] args) Q-n8~Ey1a
{ ;~EQS.Qp
new TestMethod(); d51'[?(
} Aj)Q#Fd[
} 1|(Q|
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