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)); hU2N{Ac
} JR_c]AQYu
for(int i=0;i<nEndPos.length-1;i++) f;ycQc@f
{ zgpPu4t
nEndPos = nStartPos[i+1]; ',RR*{I
} M[T!AO-S$
nEndPos[nEndPos.length-1] = nFileLength; wIbc8ze
} ]@1ncn7N
} gD fVY%[Z
|@)ij c4i
}S&SL)
//启动子线程 zjJyc?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Fn%:0j
for(int i=0;i<nStartPos.length;i++) z<P#djx
{ .~8IW,[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y!s/uvRI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qdu:kA:]
nStartPos,nEndPos,i); 9zd)[4%=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ma*9O |v^
fileSplitterFetch.start(); 55N/[{[
} DFjkp;`1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z#W`0G>'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I3aEg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _H3cqD
nEndPos = " + nFileLength); CblL1q8
// fileSplitterFetch[nPos.length-1].start(); A><%"9pZ
Ox43(S0~
Ri-wbYFaP
//等待子线程结束 sQH.}W$C
//int count = 0; &k{@:z
//是否结束while循环 j+ys&pDczm
boolean breakWhile = false; 42Ffx?Qmv
bFx?HM.AGW
W]*wxzf!5z
while(!bStop) $1@{Zz!S
{ <?nr"V
write_nPos(); *AN#D?X_
Utility.sleep(500); SO&;]YO
breakWhile = true; g%[Ruugu
QY fS-
#5I "M WA
for(int i=0;i<nStartPos.length;i++) XF$C)id2p
{ BzUx@,
if(!fileSplitterFetch.bDownOver) &]c9}Ic
{ JuI,wA
breakWhile = false; nz&JG~Qfm
break; @<sP1`1
} 5astv:p,P
} 4%{m7CK}
if(breakWhile) J\0YL\jw1K
break; .lnD]Q
\5l}5<|
Ywr{/
//count++; ?d%}K76V<
//if(count>4) Q'Tn+}B&
// siteStop(); MLb\:Ihy
} w/<hyEpxg
[)=FZF6kG
K&h|r`W(
System.err.println("文件下载结束！"); $_UF9l0
} GgYomR:
catch(Exception e){e.printStackTrace ();} 5-QXvw(TH
} tpctz~ .
"8X+F%
] ge-b\
//获得文件长度 ro{MDs
public long getFileSize() Pg36'aTe%j
{ G#C)]4[n
int nFileLength = -1; S'e2~-p0F
try{ |g{AD`
URL url = new URL(siteInfoBean.getSSiteURL()); @mazwr{B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /_|1,x-Kx
httpConnection.setRequestProperty("User-Agent","NetFox"); wtKh8^:YD
]=3O,\
5W48z%MN
int responseCode=httpConnection.getResponseCode(); k|D!0^HE[
if(responseCode>=400) hdB[H8Q
{ 2P}RZvUd
processErrorCode(responseCode); S7vE[VF5
return -2; //-2 represent access is error ;rKYWj>IR
} yiq#p"Hs
2o/`8+eJu
dw|0K+-PH
String sHeader; [8w2U%}]
_<7FR:oBZ
$%-?S]6)
for(int i=1;;i++) K/-D 5U
{ u/f&Wq/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /WfxI>v
//Utility.log(in.readLine()); |*5nr5c_L
sHeader=httpConnection.getHeaderFieldKey(i); 5,Y2Lzr
if(sHeader!=null) kR]SxG9
{ >e;f{
if(sHeader.equals("Content-Length")) Ul Iw&U
{ bRK9Qt#3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P$Q&xN<#)
break; \t@`]QzG:
} hd;I x%tq>
} JPG!cX%
else -wfV
break; gOM`I+CwT
} >``GDjcJ
} ,0bM*qob
catch(IOException e){e.printStackTrace ();} [\1l4C
catch(Exception e){e.printStackTrace ();} }nl)*l
"_j7kYAl
: 4WbDeR
Utility.log(nFileLength); k Dt)S$N4n
iurB8~Y
4#q JX)/
return nFileLength; ,be?GAq
} ZZ*k3Ce
C5UDez
-;$/<
//保存下载信息（文件指针位置） IcQ!A=lB
private void write_nPos() $lA,{Q
{ qGCg3u6
try{ ,IE0+!I
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ui!|!V-
output.writeInt(nStartPos.length); YPnJldVn
for(int i=0;i<nStartPos.length;i++) ^;Q pE
{ j:3Hm0W3
// output.writeLong(nPos); FaE orQ
output.writeLong(fileSplitterFetch.nStartPos); wtS*w
output.writeLong(fileSplitterFetch.nEndPos); %)Dd{|c
} ot#kU 8f
output.close(); GQq'~Lr5
} \r,.hUp
catch(IOException e){e.printStackTrace ();} Ky$G$H
catch(Exception e){e.printStackTrace ();} m?$G(E5
} `|Z@UPHzG
D(U3zXdO
Cpv%s 1M
//读取保存的下载信息（文件指针位置） agT[y/gb
private void read_nPos() Lu.tRZ`$38
{ MWh+h7k'
try{ v=1S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y4rJ-
int nCount = input.readInt(); | V,jd
nStartPos = new long[nCount]; >Eg.c
nEndPos = new long[nCount]; %MZDm&f>Kk
for(int i=0;i<nStartPos.length;i++) G;c0
{ kTc5KHJ7
nStartPos = input.readLong(); ![ID0}MjJ
nEndPos = input.readLong(); ULmdt
} l(\8c><m
input.close(); F6]!?@
} 1";e'?^x
catch(IOException e){e.printStackTrace ();} :k(t/*Nl3
catch(Exception e){e.printStackTrace ();} EiP&Y,vT
} *1S.9L
wf<`J/7u
Z)T@`B6
private void processErrorCode(int nErrorCode) >@"3Q`
{ UH&1c8y}
System.err.println("Error Code : " + nErrorCode); nk$V{(FJ
} (`.qG &6p
ss@}Dt^
3nC#$L-
//停止文件下载 um2s^G
public void siteStop() ::Q);
{ @j2*.ee
bStop = true; SY>,kwHO
for(int i=0;i<nStartPos.length;i++) :F w"u4WI
fileSplitterFetch.splitterStop(); vJAAAS
EJ;0ypbG
'7LJuMp$#
} FoD/Q
} 5QFXj)hR+4
//负责部分文件的抓取 sa(M66KkU
**FileSplitterFetch.java = *;Xc-_
*/ mc=!X
package NetFox; ?"<r9S|[O
-1r&s
""v`0OP&J
import java.io.*; H0b6ZA%n
import java.net.*; s.I1L?s1w?
LVFsd6:h
&J/4J
public class FileSplitterFetch extends Thread { _ kSPUP5
u"8;fS
h[ZN >T
String sURL; //File URL xAd>",=~
long nStartPos; //File Snippet Start Position p1VahjRE-
long nEndPos; //File Snippet End Position )4L%zl7
int nThreadID; //Thread's ID &kjwIg{
boolean bDownOver = false; //Downing is over |RAQ%VXm
boolean bStop = false; //Stop identical Wt)SdF=U/
FileAccessI fileAccessI = null; //File Access interface _`X#c-J
)lDIzLp
O*J_+6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y:"v=EhB
{ FH`'1iVH
this.sURL = sURL; Ad`[Rt']kI
this.nStartPos = nStart; +G!jKta7B
this.nEndPos = nEnd; x#j\"$dla
nThreadID = id; nvs}r%1'5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !G"9xrr1
} m]=oaj@9
h\u0{!@}
ULNAH`{D
public void run() rTsbP40
{ +{C9uY)$vf
while(nStartPos < nEndPos && !bStop) l@tyg7CwY
{ Yf!*OGF
kToVBU$
16[-3cJ T
try{ -#S)}NEn
URL url = new URL(sURL); C7jc6(>m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )pZekh]v
httpConnection.setRequestProperty("User-Agent","NetFox"); s7.p$r
String sProperty = "bytes="+nStartPos+"-"; ^0`<k
httpConnection.setRequestProperty("RANGE",sProperty); =##s;zj(%
Utility.log(sProperty); RhV:Z3f`6
{KU.
|,1bkJt
InputStream input = httpConnection.getInputStream(); =~\]3g
//logResponseHead(httpConnection); W3jXZ>
^)hAVf~E
kh<pLI>$h
byte[] b = new byte[1024]; %l8*t$8
int nRead; )@<HCRQ'q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SvX=isu!.
{ F%PwIB~cy
nStartPos += fileAccessI.write(b,0,nRead); uO ?Od
//if(nThreadID == 1) P>{US1t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @ kJ0K
} && DD
BLL]^qN;Y
UK"}}nO@e
Utility.log("Thread " + nThreadID + " is over!"); V\@jC\-5Vt
bDownOver = true; jF38kj3O7
//nPos = fileAccessI.write (b,0,nRead); 2/yXY_L
} /B,:<&_-
catch(Exception e){e.printStackTrace ();} S]e j=6SP
} yHWi[7$
} _e?q4>B)c
:H!(?(Pie
Ic[}V0dk
//打印回应的头信息 }A4nJ>`tq
public void logResponseHead(HttpURLConnection con) J+)'-OFt0
{ Q;$ 9qOF
for(int i=1;;i++) =zeFK_S!
{ eeW' [
String header=con.getHeaderFieldKey(i); 2E`~ qn
if(header!=null) $^W-Wmsz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u\{qH!?t
Utility.log(header+" : "+con.getHeaderField(header)); ~lzdbX
else ?YqJ.F;
break; X5uS>V%/
} K-J|/eB
} ds*m6#1b
\8;Qv
$uEJn&n7}
public void splitterStop() .UM<a Ik
{ ''#p47$8<d
bStop = true; 7"ylN"syZ
} p+, 1Fi
cPpu
g3|BE2?
} n?'d|h
rr|"r
<Ctyht0c.
/* 9pWi.J
**FileAccess.java NH'1rt(w
*//文件访问(定位，写) f>.4-a?
package NetFox; Tr}R`6d$
import java.io.*; ZlthYuJ
'oleB_B
nIfN"
public class FileAccessI implements Serializable{ TE3*ktB{N
YecT 96%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6fh{lx>
RandomAccessFile oSavedFile; |q3f]T&+>{
long nPos; B;VH`*+X
Mv|vRx^b
$bk>kbl P
public FileAccessI() throws IOException r=h8oUNEJ*
{ KwS`3 6:
this("",0); |5W8Q|>%
} e#tIk;9Xz
L>SZgmV+
E]NY (1
public FileAccessI(String sName,long nPos) throws IOException x_yF|]aI!
{ :]'q#$!
oSavedFile = new RandomAccessFile(sName,"rw"); /T,zZ9=
this.nPos = nPos; Q/p(#/y#b
oSavedFile.seek(nPos); DL,[k (
} NdZ)[f:2
SaCx)8ul0
`%|u!
public synchronized int write(byte[] b,int nStart,int nLen) XTV0Le\f
{ Qh^R Ax
int n = -1; sH%&+4!3
try{ hGvqT,'
oSavedFile.write(b,nStart,nLen); $57\u/(
n = nLen; j~epbl)pC
} m$?.Yig?
catch(IOException e) {gsW(T>)
{ EJ G2^DSS
e.printStackTrace (); T8U[xu.>
} _ \l HI
Q\|18wkW
Rb#/qkk/
return n; L;3aZt,#O
} }wfI4?}j}
F99A;M8(
?~,JY
} yxvjg\!&
(k8Z=/N~
ijFV<P
/* vO]J]][
**SiteInfoBean.java >60"p~t
*/ Ir/:d]N*
package NetFox; U+} y %3l
6}ftBmv
KSc~GP_
public class SiteInfoBean { !Av1Leb9$
ZOuR"9]
.a,(pq Jg
private String sSiteURL; //Site's URL HyEa_9
private String sFilePath; //Saved File's Path |<rfvsQ.
private String sFileName; //Saved File's Name Jn*Nao_)
private int nSplitter; //Count of Splited Downloading File _s*! t
Rboof`pVt
q!&B6]
public SiteInfoBean() cz#_<8'N
{//nSplitter的缺省值为5 FZp<|t
//default value of nSplitter is 5 vL$|9|W(
this("","","",5); r1G8]agO
} ^wJEfac
xl8#=qmCD
6.'$EtH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j&CZ=?K^c
{ *Tp]h 0
sSiteURL= sURL; >)^NJ2Fd
sFilePath = sPath; "15=ET
sFileName = sName; W`x)=y]Z
this.nSplitter = nSpiltter; 59i]
+9zA^0
x> \Bxa8
} vLDi ;
<Oa9oM},d
$)*xC!@6X
public String getSSiteURL() 2r;GcjezH
{ RdI};K
return sSiteURL; "0-y*1/m
} &SmXI5>Bo0
K/|
K]<u8eF
public void setSSiteURL(String value) #ZWl=z5aBi
{ OQFi.8
sSiteURL = value; y(v_-6b
} @9vvR7{P
(6R4 \8z2
f`|G]da-3o
public String getSFilePath() 8l23%iWxe
{ {ma;G[!
return sFilePath; J3=BE2L
} ug#<LO-.Rd
Wc|z7P~',%
E[?kGR[
public void setSFilePath(String value) HO5d%85
{ 4AHL3@x
sFilePath = value; tU:FX[&?R
} fsvYU0L
w$>3pQ8d
wmYvD<
public String getSFileName() 1[DS'S
{ &{W^W8,%
return sFileName; ?"j@;/=
} U$'y_}V
}V]eg,.BJ
l^r' $;<m
public void setSFileName(String value) t5)J;0/
{ +(mL~td01
sFileName = value; _tj&Psp
} [H,u)8)
~NNv>5t5
JJ5C}`(
public int getNSplitter() 2-v\3voN
{ cNj*E =~;
return nSplitter; "H1:0p
} =.b Y#4
l~1AT%
&&PgOFD
public void setNSplitter(int nCount) bx>i6 R2
{ 4*M@]J "
nSplitter = nCount; 5@P-g
} 3hS6jS
} A*'V+(
CgnXr/!L
c3k|G<C2
/* yVS\Q,:J9
**Utility.java \L[i9m|e
*/ 84M3c
package NetFox; iP "EA8
Q)^g3J
SI*^f\lu
public class Utility { onl>54M^
PayV,8
inF6M8 A1
public Utility() :'*DMW~
{ o6|-=FcvC
)}-$A-p#
R]QpMj%o
} &1Fply7(Ay
S()Za@ [a$
//线程睡眠 ($WE=biZ&
public static void sleep(int nSecond) ^l!L)iw
{ <k]qH-v4
try{ 7GZq|M_:y
Thread.sleep(nSecond); N5 n>
} yP\Up
catch(Exception e) Sz0+<F#5
{ k dU! kj
e.printStackTrace (); RJc%, ]:
} `6Hf&u<
} 40K2uT{cq
Eark)
//日志 \G;CQV#{9
public static void log(String sMsg) h~miP7,c<u
{ fLB1)kTS
System.err.println(sMsg); F2>%KuM
} a8s4T$
P5URvEnz:
'G#SLqZy
public static void log(int sMsg) ((MLM3zJ
{ DQgH_!
System.err.println(sMsg); 6Rz[?-mkLO
} kO ![X^V
} +1@AGJU3
*Bw#c j
:ba/W&-d
/* ULl_\5s2
**TestMethod.java OM!=ViN(=
*/ uO'/|[`8
package NetFox; o'Y#H r)/
0HbJKix!
'ZnIRE,N
public class TestMethod { ~A >oO-0K
r_2btpL^
zj20;5o>U&
public TestMethod() 6k9LxC:M
{ ///xx/weblogic60b2_win.exe mk=#\>
try{ *K)0UKBr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #s+Q{2s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .~`Y)PON
SiteFileFetch fileFetch = new SiteFileFetch(bean); _^T}_
fileFetch.start(); %h+uD^^$
} D/s?i[lb
catch(Exception e){e.printStackTrace ();} LK+felL
zilaP)5x6
{tt$w>X
} j=j+Nf$
n\ Uh
`C'}e
public static void main(String[] args) &;v!oe
{ 93D \R
new TestMethod(); K0<yvew
} e@j8T gI)
} p@tp]u`7
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