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)); 12DMb9_rp
} 1.!rq,+>1
for(int i=0;i<nEndPos.length-1;i++) +Sv`23G@
{ _,_>B8
nEndPos = nStartPos[i+1]; gBUtv|(@>[
} B;Ab`UX#t
nEndPos[nEndPos.length-1] = nFileLength; G*uy@s:
} |1X^@
} CUfD[un2D
<Rob.x3
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//启动子线程 r<cyxR~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x:b0G
for(int i=0;i<nStartPos.length;i++) @4Z>;
{ tKrr5SRb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n c:^)G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }"wWSPD
nStartPos,nEndPos,i); _C~e(/=z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %ribxgmd
fileSplitterFetch.start(); (h7 rW3
} YW9 [^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), / *xP`'T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P;bl+a'gu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \NKf$"x}
nEndPos = " + nFileLength); j0^~="p%C
// fileSplitterFetch[nPos.length-1].start(); &G7JGar
bPEf2Z G4
7kx)/Rw\B
//等待子线程结束 &0SX*KyI
//int count = 0; .x5Yfe
//是否结束while循环 )dgXS//Y
boolean breakWhile = false; 7)!(0.&
^;@q^b)ZP
_O2},9L n
while(!bStop) f305yo
{ j*nZ
write_nPos(); $cEl6(66iX
Utility.sleep(500); vpcx 1t<
breakWhile = true; `}#(Ze*V:
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for(int i=0;i<nStartPos.length;i++) -;&aU;k
{ $D +6=m[
if(!fileSplitterFetch.bDownOver) 34k<7X`I
{ v]\io#
breakWhile = false; eyf\j,xP&
break; iM+K&\{_h
} )$Xd#bzD|
} A9\m.3jo
if(breakWhile) Y,?s-AB
break; kmPK |R
"- S2${
}NW^?37
//count++; CwZ+Pn0
//if(count>4) {%5k1,/(
// siteStop(); |ybW
} uN20sD}
ps=jGh[
l4?o0;:)
System.err.println("文件下载结束！"); Yh)yp?
} &cztUM(
catch(Exception e){e.printStackTrace ();} #D M%_HXDi
} &54fFyJF
n_\VG[f
s `fIeP
//获得文件长度 O^ZOc0<
public long getFileSize() < .&t'W
{ )k@W6N
int nFileLength = -1; Ab`mID:
try{ oVutHt
URL url = new URL(siteInfoBean.getSSiteURL()); 7|LJwXQ-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (e sTb,
httpConnection.setRequestProperty("User-Agent","NetFox"); HSGM&!5mW
<6^MVaD
}MAQhXI^O|
int responseCode=httpConnection.getResponseCode(); ufAp7m@ud
if(responseCode>=400) =<w6yeko
{ d!kiWmw,
processErrorCode(responseCode); 6, \i0y5n
return -2; //-2 represent access is error JR{3n*
} <ABN/nH
RB<LZHZI
| n5F_RL
String sHeader; @Aa$k:_
!]1X0wo\
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for(int i=1;;i++) #R$d6N[H
{ |d^r"wbs3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +;~JHx.~X
//Utility.log(in.readLine()); y;Xb."e~
sHeader=httpConnection.getHeaderFieldKey(i); sPY*2B
if(sHeader!=null) n^P=a'+
{ @/h_v#W
if(sHeader.equals("Content-Length")) U">J$M@
{ -BUxQ8/,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x)0g31 49
break; 9t@^P^}=\m
} ?hUC#{
} 4GWt.+{J$
else YVt#( jl
break; @s!9T
} Kn3qq
} <"w;:Zs
catch(IOException e){e.printStackTrace ();} V\^rs41$;
catch(Exception e){e.printStackTrace ();} /.<%y8v
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Utility.log(nFileLength); 4DI.RK9
'7G'R
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return nFileLength; *O-1zIlp
} bOjvrg;Sz\
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fP>_P#gZ
//保存下载信息（文件指针位置） 0VC8'6S_k
private void write_nPos() owL>w
{ ry9%Y3
try{ ~qQSt%
output = new DataOutputStream(new FileOutputStream(tmpFile)); #mg6F$E
output.writeInt(nStartPos.length); YW55iyM
for(int i=0;i<nStartPos.length;i++) lJ.:5$2H
{ 'Lu7cb^
// output.writeLong(nPos); <>/0;J1<
output.writeLong(fileSplitterFetch.nStartPos); PD$XLZ
output.writeLong(fileSplitterFetch.nEndPos); z=1 J{]
} Kp?):6
output.close(); [tYly`F
} taOD,}c|$
catch(IOException e){e.printStackTrace ();} *0zdI<Oe
catch(Exception e){e.printStackTrace ();} *y[i~{7:
} Jydz2 zt!
)6U&^9=
H.|v^e
//读取保存的下载信息（文件指针位置） `tA~"J$32l
private void read_nPos() K];`
{ j`jF{k b
try{ !4-B xeNY\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3wZA,Z
int nCount = input.readInt(); z%cq%P8g
nStartPos = new long[nCount]; g a|RW0
nEndPos = new long[nCount]; u&Q2/Y
for(int i=0;i<nStartPos.length;i++) <#AS[Q[N
{ ,E,oz{,i(
nStartPos = input.readLong(); Ut:>'TwG
nEndPos = input.readLong(); 2g shiY8_
} 3vRRL
input.close(); SXX6EIJr|
} #xL^S9P
catch(IOException e){e.printStackTrace ();} l`c&nf6
catch(Exception e){e.printStackTrace ();} BeP]M1\?>
} =^ur@E
iaXpe]w$n
Zp'c>ty=
private void processErrorCode(int nErrorCode) 4oW6&1
{ Yw7+wc8R
System.err.println("Error Code : " + nErrorCode); 7A0D[?^xe
} <Stfqa6FJ
0}:- t^P
r;:5P%:
//停止文件下载 +~~FfIzf#
public void siteStop() 3[8F:I0UL
{ 5Y<O
bStop = true; cHN eiOF
for(int i=0;i<nStartPos.length;i++) c(Liwuj
fileSplitterFetch.splitterStop(); \uxDMKy
u&MlWKCi
Fy1@B(V%
} !GJnYDN
} a1V+doC
//负责部分文件的抓取 5IOMc4v
**FileSplitterFetch.java 'r`#u@TTZ
*/ {m1=#*
package NetFox; CZ&VP%
PDN3=PAR/A
.48Csc-
import java.io.*; E]eVoC
import java.net.*; 3I0=^>A
,G2]3 3Z
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public class FileSplitterFetch extends Thread { ,_HSvs7-
#H9J/k_
!63>II
String sURL; //File URL Z"spua5
long nStartPos; //File Snippet Start Position WjfUbKg0
long nEndPos; //File Snippet End Position r![RRa^
int nThreadID; //Thread's ID j2GO ZKy
boolean bDownOver = false; //Downing is over q2Xm~uN`)
boolean bStop = false; //Stop identical ]fc9m~0N,\
FileAccessI fileAccessI = null; //File Access interface #1-y[w/
Q'?{_
[UO?L2$&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aH@Ux?-}
{ 8yr_A[S8.
this.sURL = sURL; ;3ZHm*xJx
this.nStartPos = nStart; E]G#"EV!Y
this.nEndPos = nEnd; ?UD2}D[M
nThreadID = id; #H]cb#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 32DT]{-N!
} CXC,@T
QcZ*dI7]:
=#WoeWFW*
public void run() ?.E ixGzI^
{ o`B,Pt5vu
while(nStartPos < nEndPos && !bStop) ;dXQB>Za
{ r{DR$jD
S $wx>715
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try{ l=(4o4um
URL url = new URL(sURL); y+3< ] N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B8Ob~?
httpConnection.setRequestProperty("User-Agent","NetFox"); }e}J6[wP
String sProperty = "bytes="+nStartPos+"-"; H(qDQqJHYy
httpConnection.setRequestProperty("RANGE",sProperty); C$MaJHkiF
Utility.log(sProperty); /_Z--s>j
Pba 6Ay6B
om$x;L6
InputStream input = httpConnection.getInputStream(); A`E7V}~
//logResponseHead(httpConnection); 6=V&3|"
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byte[] b = new byte[1024]; /mMRV:pd
int nRead; N[$bP)h7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) . J"g.Q
{ *Xh)22~T
nStartPos += fileAccessI.write(b,0,nRead); /cn=8%!N
//if(nThreadID == 1) ;;z4EGr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QW
} F Qtlo+3
9qIdwDRY
oqzx}?0
Utility.log("Thread " + nThreadID + " is over!"); C'bW3la
bDownOver = true; N?!]^jI,
//nPos = fileAccessI.write (b,0,nRead); 0IHcyb
} !Pnvqgp/
catch(Exception e){e.printStackTrace ();} <0my,hAK
} uyr56
} CXqU<a&
)6?(K"T
a]NQlsE}l
//打印回应的头信息 dZnAdlJ
public void logResponseHead(HttpURLConnection con) lq2P10j@
{ HCP'V
for(int i=1;;i++) nSxFz!
{ aAY=0rCI-
String header=con.getHeaderFieldKey(i); Ns.b8Y
if(header!=null) S{cy|QD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c(@V t&gE
Utility.log(header+" : "+con.getHeaderField(header)); r)$(>/[$
else U 00}jH
break; QdaYP
} 5mNd5IM
} <0,c{e
E. @n Rj#
;B[*f?y-
public void splitterStop() YVy+1q[
{ C3|(XChqC
bStop = true; Xy{\>}i]N
} ;m/%g{oV
j6wdqa9!~
5&5 x[S8
} l4c9.'6
ur\v[k=
Sp+ zP-3
/* ;q:.&dak1
**FileAccess.java 2BA'Zu`
*//文件访问(定位，写) 9F8"(
package NetFox; f?O?2g
import java.io.*; ~m~<xtoc
b/N+X}VMN
'F[m,[T%x
public class FileAccessI implements Serializable{ %";bgU2Q
>"qnuv G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R +H0+omj
RandomAccessFile oSavedFile; <uXZ*E
long nPos; cPcp@Dp
_97A9wHj
E?> ERO3
public FileAccessI() throws IOException W79wz\a
{ 7hPiPv
this("",0); > %5<fK2
} +o]DT7W
-3 .Sr|t
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public FileAccessI(String sName,long nPos) throws IOException T%kr&XsQX
{ n_[;2XQQ
oSavedFile = new RandomAccessFile(sName,"rw"); Ew>E]Ys
this.nPos = nPos; 0zD[mt
oSavedFile.seek(nPos); ?[#nh@mI
} '0z-duu
P !:LAb(
xij`Mr
public synchronized int write(byte[] b,int nStart,int nLen) =FXO1UZ!
{ =b{wzx}e
int n = -1; P@Oq'y[
try{ i v7^!
oSavedFile.write(b,nStart,nLen); ay}}v7)GM
n = nLen; =<ngtN
} E<u6 js,
catch(IOException e) I^h^QeBis
{ $@t]0
e.printStackTrace (); 37Z@a!#
} zS]8ma
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z;? 32K
return n; #*QnO\.
} rPf<8oH
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]"Y? ZS;H
} G:'hT=8
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fUy:TCS
/* SJ(<u2J]
**SiteInfoBean.java K0hmRR=
*/ R-Y07A
package NetFox; oWg"f*
{C6,h#|pg
5U[m]W=B
public class SiteInfoBean { xY]Y
J&mZsa)4
[ +w=
private String sSiteURL; //Site's URL u>R2:i
private String sFilePath; //Saved File's Path I_|@Fn[>
private String sFileName; //Saved File's Name #~(J J
private int nSplitter; //Count of Splited Downloading File koQ\]t'*As
6M({T2e
x<_uwL2a
public SiteInfoBean() a o"\L0;{
{//nSplitter的缺省值为5 5Oh>rK(
//default value of nSplitter is 5 Uy$1X
this("","","",5); sFhmp
} .UJp#/EHs
8|FHr,
/CRZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Aj9<4N
{ KxZup\\:v
sSiteURL= sURL; hzG+s#
sFilePath = sPath; >NL4&MV:
sFileName = sName; $9LI v
this.nSplitter = nSpiltter; 7OF6;@<
v?\Z4Z|f
NJ6* 7Cd
} 6x?3%0Km
*^|.bBG
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public String getSSiteURL() ^*!Tq&Dst|
{ {<f |h)r
return sSiteURL; Yz6+ x]
} *qM)[XO
m-%.LDqM
IrIF 853g
public void setSSiteURL(String value) ,OGXH2!h
{ y2nwDw(xF
sSiteURL = value; Pe-1o#7~W
} >M~wFs$~
QQ1|]/)
CF|4, K)
public String getSFilePath() &x= PAu
{ t|/{oAj
return sFilePath; d~ m,hCTe
} (c^ZFh2]
h!>K[*
%3ieR}:/e&
public void setSFilePath(String value) s48 { R4
{ tQTVP2:Y
sFilePath = value; Gp&o
} Vifh`BSP
g!<=NVhYt
0+H4sz%.
public String getSFileName() 1?!z<<
{ gHLvzm
return sFileName; o \r6iO
} MlbQLtw
@fjVCc;
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public void setSFileName(String value) [PRQa[_
{ qKL:#ny
sFileName = value; bUcq LV
} 3W<_J_[
[\41
86_`Z$ s
public int getNSplitter() C71\9K*X
{ yu^n;gWH
return nSplitter; "2J$~2{N
} Hi V7
qj$6/V|D
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public void setNSplitter(int nCount) zQPQP`
{ oM<Y o%n
nSplitter = nCount; )p?p39>h
} &_1Ivaen6
} e#R'_}\yj
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T/9`VB%N
/* &O&;v|!9
**Utility.java G; onJ>
*/ G\\0N^v
package NetFox; xRTr@
Y1=.46Ezf
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public class Utility { 0P?\eoB@8
ggP#2I\
T?!D?YV
public Utility() |mHxkd
{ X3# AYn,
ZvSWIQ6
Y\Grf$e
} -n>JlfCd2
B'@a36
//线程睡眠 {Xj2c]A1
public static void sleep(int nSecond) iUH{rh!
{ &I=27!S
try{ v&#=1Zb
Thread.sleep(nSecond); Hea76P5$P+
} ug?])nO.C
catch(Exception e) z[E gMS!
{ r=S6yq}
e.printStackTrace (); W)OoHpdw
} dI$U{;t
} H.H$5(?O
IegZ)&_n
//日志 >sfH[b
public static void log(String sMsg) li`4&<WGC
{ X~#jx(0_
System.err.println(sMsg); JiXkW%
} [0lu&ak[&
M8,_E\*
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public static void log(int sMsg) #JLxM/5^1~
{ r6x"D3
System.err.println(sMsg); 'IykIf
} /&T"w,D
} )ld !(d=
/8s+eHn&%
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/* =Y-ZI
**TestMethod.java Qgel^"t]i
*/ X (0`"rjg
package NetFox; Wu\szI"
<z2*T \B!8
Kx@Papn|6
public class TestMethod { o`EL)K{
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J8>8@m6
public TestMethod() hM/:zC:
{ ///xx/weblogic60b2_win.exe ~\C.Nm
try{ |Qa[N(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 13lJq:bM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vw P+tM
SiteFileFetch fileFetch = new SiteFileFetch(bean); AD=qB5:
fileFetch.start(); 1(;_1@P
} QsN%a>t
catch(Exception e){e.printStackTrace ();} kM>Bk\
SD=kpf;
b;AGw3SF
} jIOrB}
B>!OW2q0D
i`F8kg`_K
public static void main(String[] args) W ^MF3
{ 5VXI/Lw#
new TestMethod(); ;rK= jz^Q
} b_p/ 1W:
} 7[)IP:I>
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