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)); @/,:". SM
} <c77GimD?
for(int i=0;i<nEndPos.length-1;i++) M(/ATOJ(
{ >2t.7UhDI
nEndPos = nStartPos[i+1]; -k8<LR3
} mfqnRPZ
nEndPos[nEndPos.length-1] = nFileLength; !*1$j7`tP
} bt{b%r
} VtN1 [}
?:$\ t?e^
!sG#3sUe[
//启动子线程 2z9s$tp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J6I:UML
for(int i=0;i<nStartPos.length;i++) T!7B0_
{ 8g0VTY4$jP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X`6"^ xme
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IE|? &O
nStartPos,nEndPos,i); dfP4SJqq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XkPE%m_5D
fileSplitterFetch.start(); jQrj3*V
} vh#81}@N7*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B[,AR"#b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8<)ZpB,7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $<QrV,T
nEndPos = " + nFileLength); Rb!y(&>v
// fileSplitterFetch[nPos.length-1].start(); SK*z4p
Qhq' %LR
VIHuo,
//等待子线程结束 ,v%'2[}
//int count = 0; c'.XC}
//是否结束while循环 >qz#&
boolean breakWhile = false; Vw|P;LLl`
V3>tW,z
dEZUK vo
while(!bStop) N;']&f
{ B<Q)z5KK
write_nPos(); n$F~
Utility.sleep(500); l*?_@
breakWhile = true; E<jW;trt_
1<tJ3>Xl
vc :%
for(int i=0;i<nStartPos.length;i++) ?<`oKBn
{ >%ovL8F
if(!fileSplitterFetch.bDownOver) :r(dMU3%
{ ZTibF'\5N
breakWhile = false; $g^D1zkuDT
break; aeISb83Y|
} WfD fj
} 1uO2I&B
if(breakWhile) ^v`naA(
break; S,j. ?u*!
?ac4GA(
=W &Mt
//count++; QgI[#d{
//if(count>4) d[>HxPwo
// siteStop(); iy8Jl
} 0-uw3U<
>.6|\{*sG
lXg5UrW
System.err.println("文件下载结束！"); $&=xw _
} 5f{P% x(
catch(Exception e){e.printStackTrace ();} hLbWqF
} @)BO`;*$fF
>MGWN
fd4C8>*7G
//获得文件长度 n m<?oI*\
public long getFileSize() f"KrPx!^b
{ 1$8@CT^m
int nFileLength = -1; j)2I+[aoB
try{ <)p.GAZ
URL url = new URL(siteInfoBean.getSSiteURL()); r=&,2meo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [lg!*
httpConnection.setRequestProperty("User-Agent","NetFox"); .07`nIs"
IH;sVT$M
CVWT>M<
int responseCode=httpConnection.getResponseCode(); ujRXAN@mC
if(responseCode>=400) ICb!AsL
{ #n'.a1R
processErrorCode(responseCode); GPGE7X'
return -2; //-2 represent access is error "bIb?e2h9G
} {Q3OT
~g\~x
1!KROes4
String sHeader; 2}A)5P*K
|L8 [+_m
\c -m\|
for(int i=1;;i++) a$"nNmD?
{ Td'Mc-/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \y5lYb,*c_
//Utility.log(in.readLine()); Ln4]uqMG.
sHeader=httpConnection.getHeaderFieldKey(i); 7ocUFY0"
if(sHeader!=null) DxV=S0P
{ =3.dgtH
if(sHeader.equals("Content-Length")) T@tsM|pI
{ SvT0%2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7a1o#O
break; ->rqr#
} 3'Y-~^ml|
} 68XJ`/d
else pL"{Uqi
break; (N}-]%#
} E{<#h9=>
} #NW+t|E
catch(IOException e){e.printStackTrace ();} \ZZ6r^99
catch(Exception e){e.printStackTrace ();} ~t)cbF(UO
uQIPnd(V
u%~'+=
Utility.log(nFileLength); i%-yR DIX
`(FjOd K
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return nFileLength; 2y - QH
} 1'qXT{f/~
~HB#7+b
9wYm(7M6
//保存下载信息（文件指针位置） lxyTh'
private void write_nPos() pi?/]}:
{ ,VS\mG/}s
try{ = LNU%0m
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rn~'S2`u
output.writeInt(nStartPos.length); ^2~ZOP$A
for(int i=0;i<nStartPos.length;i++) 1 pVw,}
{ \J+a7N8m,
// output.writeLong(nPos); )#m{"rk[x,
output.writeLong(fileSplitterFetch.nStartPos); 98Vv K?
output.writeLong(fileSplitterFetch.nEndPos); ~6f/jCluR%
} #c:s2EL
output.close(); FOQ-KP\=,
} sfX~X/
catch(IOException e){e.printStackTrace ();} ;j26(dH
catch(Exception e){e.printStackTrace ();} rWTaCU^qV
} h-96 2(LG
9i\RdJv.
|8'}mjs.Q
//读取保存的下载信息（文件指针位置） Gd 4S7JE
private void read_nPos() ;0dH@b
{ k*C69
try{ LO_Xrj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @} r*KF-
int nCount = input.readInt(); h>`[p,o
nStartPos = new long[nCount]; }dN\bb{#
nEndPos = new long[nCount]; zIF1A*UH
for(int i=0;i<nStartPos.length;i++) BQ6$T&
{ `j{3|C=
nStartPos = input.readLong(); }ppApJT
nEndPos = input.readLong(); (2;Aqx5i
} 5;XC!Gz
input.close(); 8'Q+%{?1t
} >V^8<^?G
catch(IOException e){e.printStackTrace ();} <9]"p2
catch(Exception e){e.printStackTrace ();} k M/:n
} r ~{nlLO}
&u:U"j
<#:iltO
private void processErrorCode(int nErrorCode) $*{,Z<|2
{ Nf4@m|#
System.err.println("Error Code : " + nErrorCode); ;j T{< Y
} \Q#pu;Y*N]
tV=Qt[|@
~~{lIO)&
//停止文件下载 0")_%
public void siteStop() ]4t1dVD
{ tXzuP_0
bStop = true; efyEzL
for(int i=0;i<nStartPos.length;i++) Ue9d0#9
fileSplitterFetch.splitterStop(); glch06
qg j;E=7
KYTXf+oh
} eV_",W
} s1OSuSL>
//负责部分文件的抓取 z/j*zU `
**FileSplitterFetch.java ]fY:+Ru
*/ #IppjaPl8
package NetFox; F4=X(P_6
-qSGa;PJ
R UCUEo63
import java.io.*; k6 OO\=
import java.net.*; xRZ K&vkKE
GB+$ed5@<
k7JC~D E#
public class FileSplitterFetch extends Thread { #pWy%U
1^AQLOiRE1
.5HD i-
String sURL; //File URL <OiH%:G/1
long nStartPos; //File Snippet Start Position "wVisL2+.
long nEndPos; //File Snippet End Position .D7Gog3^<
int nThreadID; //Thread's ID JiqhCt\
boolean bDownOver = false; //Downing is over Wu,=jL3?$A
boolean bStop = false; //Stop identical kJ* N`=
FileAccessI fileAccessI = null; //File Access interface jz3f{~
G=e'H-
e9\_H=t+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException de8xl
{ )"Ujx`]4r
this.sURL = sURL; {DVMs|5;^
this.nStartPos = nStart; (wH+0
this.nEndPos = nEnd; [$6YPM>Ee
nThreadID = id; akj#.aYk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "Z';nmv'N
} ;Gu(Yoa}y
_+Z;pt$C
Vf(..8
public void run() OZKZv,
{ ,\T`gh
while(nStartPos < nEndPos && !bStop) =BD|uIR
{ X&Ospl@H
*>GRU8_}
>YdLB@
try{ Zirp_[KZ%
URL url = new URL(sURL); un`4q-S7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PTQN.[bBh
httpConnection.setRequestProperty("User-Agent","NetFox"); Vo%ikR #
String sProperty = "bytes="+nStartPos+"-"; Nbf>Y
httpConnection.setRequestProperty("RANGE",sProperty); Lm^vS u
Utility.log(sProperty); Dz$dJF1 8
OSJL,F,
$|@-u0sv
InputStream input = httpConnection.getInputStream(); l>oJ^J
//logResponseHead(httpConnection); !h^_2IX
:VR%I;g;
ihct~y-9W
byte[] b = new byte[1024]; f(EO|d^u
int nRead; a!j{A?7Kw.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h5n@SE>G
{ V_4=0(
nStartPos += fileAccessI.write(b,0,nRead); y :QnK0
//if(nThreadID == 1) /BS yanro
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !@h)3f]`1G
} gd0a,_`M
{(d 6of`C_
7 $dibTER
Utility.log("Thread " + nThreadID + " is over!"); t#!AfTY$w
bDownOver = true; Vc8w[oS
//nPos = fileAccessI.write (b,0,nRead); U*BI/wZ
} :c:}_t{%
catch(Exception e){e.printStackTrace ();} yx<-M
} E]pDp /D
} XCGK&OGI
y+',jM
8%Ak
//打印回应的头信息 cVaGgP}\
public void logResponseHead(HttpURLConnection con) _]< Tv3]RK
{ #Fh:z4
for(int i=1;;i++) rwpH9\GE
{ 3'55!DE
String header=con.getHeaderFieldKey(i); d263#R
if(header!=null) )SaMfP1=v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8wCB}qC
Utility.log(header+" : "+con.getHeaderField(header)); ,}^FV~
else Rz<'&Z>;
break; "!#KQ''R
} HC$}KoZkC
} IRsyy\[kp8
cOdgBi
o#-^Lg&
public void splitterStop() ^HWa owy=
{ .p78 \T
bStop = true; Hr(%y&0
} Dyj>dh-
+@+*sVb
k P=~L=cK
} `cFNO:
{afIr1j/m
%/r:iD
/* wYd{X 8$
**FileAccess.java xeRoif\4c
*//文件访问(定位，写) SM.KM_%K
package NetFox; L}tP_ *
import java.io.*; I9sQPa
.bNG:y>
1 l-Y)
public class FileAccessI implements Serializable{ N3\vd_D(
T=[/x=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2GRv%:rZ
RandomAccessFile oSavedFile; v+DXs!O{
long nPos; NqN}] nu6
gq.l=xS
CH0Nkf
public FileAccessI() throws IOException j HEt
{ m :2A[H+
this("",0); p|w0 i[hc
} Z1U@xQj
I(qFIV+HR
"8\2w]"
public FileAccessI(String sName,long nPos) throws IOException _rW75n=3b7
{ PebyH"M(
oSavedFile = new RandomAccessFile(sName,"rw"); Eg_ram`\R
this.nPos = nPos; Wfsd$kN6{
oSavedFile.seek(nPos); O-n JuZJgX
} ]}9[ys
lB
HDj260a
public synchronized int write(byte[] b,int nStart,int nLen) Ed1y%mR>
{ O_v*,L!
int n = -1; 8-x)8B
try{ B|r'
oSavedFile.write(b,nStart,nLen); -7VQ{nC
n = nLen; yXCHBz6&
} %0%Tp
catch(IOException e) tcJN`N
{ D/Py?<n-B
e.printStackTrace (); 2~%^y6lR
} *_K*GCy
/1b7f'
/sdZf|Zl
return n; sE[ Yg8yAt
} h*\u0yD)
[-VIojs+u
@jKB[S;JSn
} &W*^&0AV
sAoxLI
&BN#"- J
/* No*[@D]g
**SiteInfoBean.java @DSKa`
*/ -[[(Zx
package NetFox; ~,.;2K73
_7'5IA
dd*p_4;
public class SiteInfoBean { ZWQ/BgKB
@I#uv|=N
[OR"9W&
private String sSiteURL; //Site's URL k`J|]99Wb
private String sFilePath; //Saved File's Path }lGui>/D
private String sFileName; //Saved File's Name |^"0bu"
private int nSplitter; //Count of Splited Downloading File w[AL'1s]
^%!#Q].
%Rk DR
public SiteInfoBean() \J;_%-Z
{//nSplitter的缺省值为5 1:J+`mzpl
//default value of nSplitter is 5 w1eFm:'
this("","","",5); =Q*3\)7
} A#Y:VavQ?
jwP5pu
^!gq_x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9dWz3b1[]
{ ',/2J0_
sSiteURL= sURL; bAwKmk9C
sFilePath = sPath; gFsqCx<q
sFileName = sName; rR 86D
this.nSplitter = nSpiltter; D"%>
Sb(OG 6
<. *bJ
} n~.$iN
?wFL\C
b`@J"E}
public String getSSiteURL() d</F6aM\
{ 5lM2nhlf'b
return sSiteURL; ?'_6M4UKa
} u1=K#5^
);kD0FO1|
-:E~Z_J`
public void setSSiteURL(String value) v*%52_
{ m xqY
sSiteURL = value; T5z]=Pd"^
} fP\q?X@]E
h9/fD5
ncMzHw
public String getSFilePath() 2;0eW&e
{ }pIn3B)
return sFilePath; Pc2!OQC'""
} @5ud{"|2
Ri~$hs!
)BvMFwQG
public void setSFilePath(String value) }>d
{ :mW< E
sFilePath = value; Q$v00z]f*
} *mbzK*
ft$RF
~UZ3 lN\E
public String getSFileName() Ikw@B)0}
{ Fx|`0LI+C
return sFileName; O9ps?{g
} RB4 +"QUh
9)NKI02M|
U||GeEd
public void setSFileName(String value) 3%5a&b
{ }\Rmwm-
sFileName = value; gXJBb+P
} *=.~PR6W{
)*>wa%[-q
xcU!bDV
public int getNSplitter() }cr'o"4
{ ?-vWNv
return nSplitter; q]I aRho
} bXOKC
66,(yxg
{;u,04OVK
public void setNSplitter(int nCount) UZ2_FP
{ Hf?@<4
nSplitter = nCount; mn?F;=qE
} 6dR+qJa6i
} jJ$B^Y"4
LSou]{R
4d5c]%
/* #0aBQ+_8H
**Utility.java E6TeZ%g
*/ R+Hu?Dv&F
package NetFox; {MUiK5:
oxlor,lw/
Lc{arhN
public class Utility { Vb`Vp(>AU
e=OHO,74z"
!Ud'(iGa
public Utility() 5lG\Z?
{ >,{sFc
OX]$Xdb2:
sX%n`L
} hLLSmW(
?[Lk]A&"L2
//线程睡眠 Z)`)9]*
public static void sleep(int nSecond) .P)lQk\
{ Snf_{A<
try{ ][$I~nRf
Thread.sleep(nSecond); >o?v[:u*
} >>P5 4|&
catch(Exception e) 2e1KF=N+
{ p@^G)x
e.printStackTrace (); 5)!g.8-!
} (?|M'gZ
} 5[ zN M
)RJEOl1
//日志 ^9[Q;=R
public static void log(String sMsg) kcCCa@~v
{ F}nwTras
System.err.println(sMsg); Gaix6@X6'
} AEyvljv
1#A$&'&\J;
e3p|g]
public static void log(int sMsg) q Q\j
{ la3B`p
System.err.println(sMsg); WA`A/`taT
} pZnp!!G
} tqGrhOt
L.HeBeO
nq M7Is
/* L^sjV/\oW
**TestMethod.java U] LDi8
*/ dJ"M#X!Zu
package NetFox; ``-N2U5
5RP kAC
/|0-O''
public class TestMethod { [;u#79aE
CvoFt=c$jE
E/zf9\
public TestMethod() 6_j |@
{ ///xx/weblogic60b2_win.exe n>Ff tVZNJ
try{ ){;XI2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jeC=s~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6mM9p)"$
SiteFileFetch fileFetch = new SiteFileFetch(bean); '2(m%X\6
fileFetch.start(); \9?[|m z
} =Hi@q "
catch(Exception e){e.printStackTrace ();} M8/a laoT
l=~!'1@L}
5J5?cs-!
} 'cD?0ou`o
Tq1\
gEh/m.L7
public static void main(String[] args) MGg(d
{ =X$ieXq|
new TestMethod(); G@8)3 @
} :{7+[LcH7
} IG^@VQ%
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