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)); ;NPbEPL[5
} )k6O
for(int i=0;i<nEndPos.length-1;i++) Z~6PrM-M
{ Hq!|(
nEndPos = nStartPos[i+1]; j1i<.,0g
} &Ndq^!e
nEndPos[nEndPos.length-1] = nFileLength; d3&l!DoX
} `&/~%>
} Z9p`78kYyh
*Hed^[sO
( SiwO.TZ
//启动子线程 4<<T#oW.:G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;vp[J&=
for(int i=0;i<nStartPos.length;i++) q'CtfmI`r=
{ yr[HuwU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3aERfIJyE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %Q.|qyq
nStartPos,nEndPos,i); )mh,F#"L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jr3FDd]
fileSplitterFetch.start(); b75en{aDi*
} D"ecwx{%;C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @mm~i~~KA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lCxPR'C|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IRY/0v
nEndPos = " + nFileLength); .H7xG'$
// fileSplitterFetch[nPos.length-1].start(); F&)(G\
P+(q38f[
jImw_Q
//等待子线程结束 N}X7g0>hV
//int count = 0; %WO4uOi:@
//是否结束while循环 pUm|e5
boolean breakWhile = false; ]]!&>tOlI
!Jk|ha~r
Wo,"$Z6B
while(!bStop) K;P<c,9X/
{ N*6lyFcg
write_nPos(); -XMWN$Ah
Utility.sleep(500); ^w+)A;?W
breakWhile = true; DUlvlQW
=BVBCh
+H6cZ,
for(int i=0;i<nStartPos.length;i++) $I4:g.gKpG
{ /~}<[6ZGCY
if(!fileSplitterFetch.bDownOver) mj|TWDcj+
{ rw%1>]os
breakWhile = false; Mx_O'D
break; JzZ@Z8%a;
} {-.ZFUZmT
} y25L`b
if(breakWhile) c7f11N!v>b
break; ]Z=O+7(r
! ~3zp L
xt=ELzu$
//count++; V2/?1
//if(count>4) lL6W:Fq@(
// siteStop(); Y9ipy_@_?
} XyrQJ}WR|
i=aK ?^+
2NvbQ 3c5
System.err.println("文件下载结束！"); W*.6'u)9
} rlP?Uh
catch(Exception e){e.printStackTrace ();} ty-erdsP
} (GB*+@
:7 OhplI
DWmViuZmL
//获得文件长度 "C'T>^qw*
public long getFileSize() u3])_oj=
{ D{G~7P\.
int nFileLength = -1; {"n=t`E)3
try{ &KPJB"0L
URL url = new URL(siteInfoBean.getSSiteURL()); -_+,HyJP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O]%Vh l
httpConnection.setRequestProperty("User-Agent","NetFox"); q&d5V~q
R~!md
-YJ4-]Z
int responseCode=httpConnection.getResponseCode(); b1Fd]4H3P
if(responseCode>=400) MGfIA?u
{ _h0hl]rf
processErrorCode(responseCode); Z;[f,Oj
return -2; //-2 represent access is error 3JXKpk?
} Kp?j\67S
K3-Cuku
U2HAIV8
String sHeader; .u\xA7X
Q@5v> `
/& wA$h
for(int i=1;;i++) /@feY?glc
{ L6n<h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5rlZ'>I.
//Utility.log(in.readLine()); s8|Fe_
sHeader=httpConnection.getHeaderFieldKey(i); t;L7H E@Y
if(sHeader!=null) d[$YTw
{ .g52p+Z#
if(sHeader.equals("Content-Length")) ]JvZ{fA%*
{ d8%sGH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qfa[KD)!aB
break; o7 1f<&1
} 5KRI}f
} H`EsFKw\%
else $Fik]TbQp
break; ,Uu#41ZOKL
} (8jQdbZU
} q~G@S2=}0}
catch(IOException e){e.printStackTrace ();} ew 4pAav
catch(Exception e){e.printStackTrace ();} 8G?OZ47k#
*7G5\[gI$
5~\GAjf
Utility.log(nFileLength); {bMOT*X=A
WNWtQ2]
yYn7y1B
return nFileLength; tq&CJvJ4
} 9f_Qs4
Ae|bAyAK
;b;Bl:%?
//保存下载信息（文件指针位置） vd#BT$d?
private void write_nPos() #Pe|}!)u
{ I.hy"y2&
try{ }CB9H$FkCY
output = new DataOutputStream(new FileOutputStream(tmpFile)); |P(8T'
output.writeInt(nStartPos.length); k btQ
for(int i=0;i<nStartPos.length;i++) )F65sV{
{ B'!I{LC
// output.writeLong(nPos); gib'f@i;
output.writeLong(fileSplitterFetch.nStartPos); S/)yi
output.writeLong(fileSplitterFetch.nEndPos); /{FSG!
} 35Cm>X
output.close(); akV-|v_
} JHCXUT-r{
catch(IOException e){e.printStackTrace ();} dz=pL$C
catch(Exception e){e.printStackTrace ();} -i*]Sgese
} /j;HM[
MoMxKmI
WI\jm&H r
//读取保存的下载信息（文件指针位置） $[{YE[a
private void read_nPos() 7Kn}KO!Y8
{ 4'GosQ85
try{ 6![}Jvu>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QM4O|x[
int nCount = input.readInt(); @nxpcHj
nStartPos = new long[nCount]; )POU58$
nEndPos = new long[nCount]; !]2`dp\!
for(int i=0;i<nStartPos.length;i++) 9Z lfY1=
{ $3yn-'o'A
nStartPos = input.readLong(); eh}I?:(a?
nEndPos = input.readLong(); cs7K^D;.V
} c%5Suu(J6
input.close(); /[,0,B9!3
} p%ZAVd*|#V
catch(IOException e){e.printStackTrace ();} N.dcQQ_iS
catch(Exception e){e.printStackTrace ();} RLR\*dL1
} !T RU
E5 uk<e_
:@K~>^+U
private void processErrorCode(int nErrorCode) ?eOw8Rom
{ Fb<fQIa
System.err.println("Error Code : " + nErrorCode); gRg8D{
} z(Q 5?+P
mae@L
\.Z /
//停止文件下载 n7(/ml+Q_
public void siteStop() ?#Y1E~N
{ u -A_l<K
bStop = true; wrAcVR
for(int i=0;i<nStartPos.length;i++) bD<hzOa
fileSplitterFetch.splitterStop(); P`OZoI$bV
K?eY<L
L)9uBdF
} ((T6z$:hA
} 9a0|iy
//负责部分文件的抓取 UaXWHCm`
**FileSplitterFetch.java X{tfF!+iy
*/ CM4#Nn=i~
package NetFox; - sL4tMP
!;M5.Y1j&"
wH]Y1 m
import java.io.*; tqzr+
import java.net.*; ~vB dq Yj
@|d+T"f
PXo^SHJ+gt
public class FileSplitterFetch extends Thread { k@^T<Ci
)}i|)^J
:aWC6"ik-W
String sURL; //File URL $\q}A:
long nStartPos; //File Snippet Start Position l,:>B-FV
long nEndPos; //File Snippet End Position 5~{s-Ms
int nThreadID; //Thread's ID _NN5e|t
boolean bDownOver = false; //Downing is over F~wqt7*
boolean bStop = false; //Stop identical Pv3qN{265
FileAccessI fileAccessI = null; //File Access interface Lv7$@|"H9
{)PgN
} bm ^`QY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .wf$]oQQ
{ 'pC51}[A{^
this.sURL = sURL; C(&3L[
this.nStartPos = nStart; wkKSL
this.nEndPos = nEnd; 51Q~/
nThreadID = id; xbD]EC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g]jCR*]
} g<^-[w4/
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,$bK)|pGV
public void run() u+qj_Ej
{ SY$%)(c8kL
while(nStartPos < nEndPos && !bStop) %OJq(}
{ )M_|r2dDq3
%,f(jQfg_
S#N4!"
try{ Ah_0o_Di
URL url = new URL(sURL); epG!V#I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lN'b"N
httpConnection.setRequestProperty("User-Agent","NetFox"); X][=(l!;w7
String sProperty = "bytes="+nStartPos+"-"; }TRVCF1
httpConnection.setRequestProperty("RANGE",sProperty); +l;AL5h
Utility.log(sProperty); b] ~
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S^_F0</U,
InputStream input = httpConnection.getInputStream(); @waY+sqt=
//logResponseHead(httpConnection); d'[]
iyP0;$
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byte[] b = new byte[1024]; 7uq^TO>9f
int nRead; Ny G?^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #]z_pp:
{ @6%o0p9zz
nStartPos += fileAccessI.write(b,0,nRead); M?QX'fia
//if(nThreadID == 1) gXe`G(w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l(d3N4iz
} #A=ER[[
Yz? 8n
zR5KC!xc
Utility.log("Thread " + nThreadID + " is over!"); TV~S#yg+H
bDownOver = true; 91M5F$
//nPos = fileAccessI.write (b,0,nRead); ]}L tf,9
} s3y"y_u
catch(Exception e){e.printStackTrace ();} S@cKo&^
} (lt{$0
} |Q$9I#rv
Wd?=RO`a
s^HI%mdf
//打印回应的头信息 ]K|td)1X
public void logResponseHead(HttpURLConnection con) qqSFy>`P
{ OPC8fX5.
for(int i=1;;i++) xM**n3SZ`
{ gmN$}Gy}
String header=con.getHeaderFieldKey(i); liPaT
if(header!=null) +^ `n- m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JzmX~|=Xi
Utility.log(header+" : "+con.getHeaderField(header)); <\oD4EE_
else X9;51JV
break; ;nAI;Qw L
} > *soc!#Y
} [Nu py,v
nJY3 1(p
G(gZL%M6
public void splitterStop() ;@H:+R+(
{ c{[lT2yxU
bStop = true; UeU`U
} f47dB_{5f.
R7/ET"
g9gi7.'0
} remRmY?
T+41,
$Z<x r
/* @@H?w7y?&
**FileAccess.java >J/8lS{#
*//文件访问(定位，写) uMX\Y;N
package NetFox; Y{9xF8#
import java.io.*; <aQ5chf7
#3_ @aq*
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public class FileAccessI implements Serializable{ wicW9^ik
dZCnQIS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v(=E R%
RandomAccessFile oSavedFile; LvNulMEK
long nPos; 75;g|+
Nf%/)Tk
mX[J15
public FileAccessI() throws IOException {_UOS8j7
{ e*M-y C
this("",0); ,O_iSohS
} aUq2$lw1
Dq+S'x~>
Rw)=<XV)6
public FileAccessI(String sName,long nPos) throws IOException (e4#9
{ Y|ErVf4
oSavedFile = new RandomAccessFile(sName,"rw"); QypUBf
this.nPos = nPos; #'BPW<Ob
oSavedFile.seek(nPos); 8wMwS6s:
} <YvW /x
a"^rOiXR{
wY3|5kbDj
public synchronized int write(byte[] b,int nStart,int nLen) eu'S~c-l
{ ^w_\D?
int n = -1; =3EjD;2
try{ 'oF XNO
oSavedFile.write(b,nStart,nLen); Q096M 0m
n = nLen; y7x*:xR[
} 6N[X:F 3`,
catch(IOException e) fWyXy%Qq
{ Mk}*ze0%
e.printStackTrace (); +asO4'r
} !o\e/HGc!
!,R=6b$E5
RLfB]\w
return n; >fzFNcO*
} MqRJ:x
kAq#cLprG
}8'b}7!
} 6[-[6%o#z
KPA.5,ai
0<+eN8od.
/* u}89v1._Jn
**SiteInfoBean.java b-RuUfUn0
*/ ~~q>]4>
package NetFox; }6gum
I.it4~]H
D9!$H!T _
public class SiteInfoBean { ?hYWxWW
J3$@: S'
tGF3Hw^mS
private String sSiteURL; //Site's URL tac\Ki?
private String sFilePath; //Saved File's Path 6G{ Q@
private String sFileName; //Saved File's Name $e:bDZ(hjj
private int nSplitter; //Count of Splited Downloading File #I\" 'n5M
}=|plz}
zbjV>5
public SiteInfoBean() nH B
{//nSplitter的缺省值为5 Zgo%Jo
//default value of nSplitter is 5 y-{?0mLq
this("","","",5); } L_Zmi$
} LCW}1H:Q
Pbt7T Q
#7@p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -q\Rbb5M
{ ^I)+u>fJ
sSiteURL= sURL; U+zntB
sFilePath = sPath; qfjUJ/
sFileName = sName; $W%-Mm
this.nSplitter = nSpiltter; D@kf^1G
;=WwJ Np~
'4CD }
} KDb`g}1Q
0{
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public String getSSiteURL() y+KAL{AGK
{ 'V&Tlw|
return sSiteURL; :(@P *"j
} )_Z^oH ]<
hzT)5'_
Wg20H23XW
public void setSSiteURL(String value) '.C#"nY>1
{ UuC-R)
sSiteURL = value; h1l%\3ZH
} &x;n^W;#
>P]gjYN
@C^wV
public String getSFilePath() g@T}h[
{ #2Iag'4T
return sFilePath; SPXvi0Jg
} e\O-5hp7
*+nw%gZG
g> ~+M
public void setSFilePath(String value) $/|vbe,
{ g>k?03;
sFilePath = value; w*&vH/D
} Y B,c=Wx
kW1w;}n$
@_7rd
public String getSFileName() n$v4$_qS
{ WA0D#yuJ/
return sFileName; pWq+`|l$
} o\]U;#YD
'.M4yif\g
43]y]/do
public void setSFileName(String value) v5@M 34
{ b%vIaP|]B
sFileName = value; Sc/$2gSG
} <XQwu*_\
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public int getNSplitter() 2pU'&8
{ ?~4x/d%
return nSplitter; v/=\(
} >^GV #z
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<i]0EE}%
public void setNSplitter(int nCount) s]|tKQGl,
{ 79D~Mau#
nSplitter = nCount; t 7o4 aBl"
} 1U/RMN3`
} )RT?/NW
([}08OW@
9[;da
/* }WaZ+Mdg\
**Utility.java "qd|!:bE
*/ 9x|`XAB
package NetFox; C#^y{q
jT}={[9b
MtaGv#mJ
public class Utility { ^m&I^\
:8hI3]9
miu?X!
public Utility() }z$_!)/i
{ dR;N3KwY
#o7)eKeQ
E}v8Q~A(
} }Z FoCMM
|w54!f6w_
//线程睡眠 /t`\b [
public static void sleep(int nSecond) 6ulx0$[
{ 2[HPU M2>
try{ GK!@|Kk8q7
Thread.sleep(nSecond); T^(W _S
} oBo*<6
catch(Exception e) {it}\[3
{ tx~,7TMS/
e.printStackTrace (); ~!qnKM>[
} jC4>%!{m
} u~ipB*Zf
=gD)j&~}_
//日志 X%j`rQk`
public static void log(String sMsg) {H)hoAenA
{ {+=hYB|&
System.err.println(sMsg); P.C?/7$7Z+
} R54ae:8
I;%1xdPt
\X _}\_c,d
public static void log(int sMsg) _uLpU4# ?
{ BDvkY
System.err.println(sMsg); ,]7ouH$H}
} HI 1T
} t(6]j#5
}DS%?6}Sy
GIH{tr1:<
/* wT\BA'VQ
**TestMethod.java 't&1y6Uu
*/ \t&! &R#
package NetFox; TB* t^E
G}g;<,g~
6XF Ufi+
public class TestMethod { ]vvA]e
Sx'oa$J
Eu'E;*-f
public TestMethod() S.~L[iLc
{ ///xx/weblogic60b2_win.exe L"vrX
try{ _ia&|#n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O- QT+]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8wvHg_U6W
SiteFileFetch fileFetch = new SiteFileFetch(bean); o>C,Db~L/
fileFetch.start(); 2HmK['(
} ch]Qz[d
catch(Exception e){e.printStackTrace ();} T`":Q1n
<O0tg[ub
i0K 2#}=^
} (ct1i>g
os"R'GYmf
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public static void main(String[] args) VsL,t\67
{ \-pwA j?
new TestMethod(); L?+N:G
} g;'S5w9S
} H=C~h\me?
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