http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); '2 Y8
} 7M8cF>o
for(int i=0;i<nEndPos.length-1;i++) q;*'V9#
{ k(o(:-+x
nEndPos = nStartPos[i+1]; m_.9PZ
} L/In~'*-
nEndPos[nEndPos.length-1] = nFileLength; W]XM<# ^^
} 2_ 1RJ
} 2|ej~}Y
q"EW*k+ )
X}Om)WCr
//启动子线程 n.t5:SW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;M~9Yr=1
for(int i=0;i<nStartPos.length;i++) a,(nf1@5
{ TO.STK`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #%w+PL:*O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), maeQ'Sv_&
nStartPos,nEndPos,i); oY0*2~sg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t2Jf+t_B7
fileSplitterFetch.start(); c91^7@Xv
} %|D)U>o{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zu2`IzrG#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JY@bD:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vG7Mk8mIr
nEndPos = " + nFileLength); \Zh&[D!2
// fileSplitterFetch[nPos.length-1].start(); ay|jq"a
iJj!-a:z.
w}#3 pU<<
//等待子线程结束 UBJYs{zz
//int count = 0; Nu3gkIz5z-
//是否结束while循环 ?XP4kjJ
boolean breakWhile = false; D+BiclJ
-%| ] d ;
;Yv{)@'Bc
while(!bStop) `wZ
{ y5F"JjQAa
write_nPos(); BMI`YGjY1
Utility.sleep(500); `e fiX^
breakWhile = true; %?, 7!|Ls
!#~KSO}zW2
^$}O?y7O
for(int i=0;i<nStartPos.length;i++) k`&FyN^)
{ :J_UXtx
if(!fileSplitterFetch.bDownOver) #Hz9@H
{ 'CSjj@3X
breakWhile = false; v*0J6<
break; d2V\T+=
} I?E+
} 8)>T>-os
if(breakWhile) SP/b4
break; y10W\beJ
m mZP;
h Ypj
//count++; {&XTa`C
//if(count>4) tzfyS#E
// siteStop(); )+|wrK:*v
} M$.bC0}T
S>r}3,]S
YtKT3u:x
System.err.println("文件下载结束！"); ]f?r@U'AS|
} 7)[2Ud8
catch(Exception e){e.printStackTrace ();} jMCd`Q]K
} q,<l3rIn
6rj iZ%
xf/K+
//获得文件长度 .AOc$Nt
public long getFileSize() s,f2[6\Y
{ ms;zC/
int nFileLength = -1; ]kx<aQ^
try{ a'/C)fplL
URL url = new URL(siteInfoBean.getSSiteURL()); G6qZ>-GiL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8_w6% md
httpConnection.setRequestProperty("User-Agent","NetFox"); 'jMs&
-:pVDxO
G_5{5Ar
int responseCode=httpConnection.getResponseCode(); Y0kcxpK/
if(responseCode>=400) kr|r-N`
{ (T$cw(!
processErrorCode(responseCode); *3E3,c8{A
return -2; //-2 represent access is error 5'+g[eNyBV
} }No#_{
y9]7LETv\M
|bSAn*6b
String sHeader; {D^ )%{
ky]^N)
,/GFD[SQ
for(int i=1;;i++) tmoCy0qWz
{ m1jEky(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7Hv6>z#m
//Utility.log(in.readLine()); 2bLc57j{`9
sHeader=httpConnection.getHeaderFieldKey(i); [%R?^*]
if(sHeader!=null) re/u3\S
{ f4*(rX
if(sHeader.equals("Content-Length")) {fDRVnI?
{ \p(0H6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -zMvpe-am&
break; $*$4DG1gaR
} &Ep$<kx8
} VyNF)$'T
else CQ<d
break; Ye4 &4t
} Sin)]zG~0
} UMBeY[?
catch(IOException e){e.printStackTrace ();} G~.VW48{n
catch(Exception e){e.printStackTrace ();} x=a#|]ngG
^GrSvl}v'
K$D+TI)
Utility.log(nFileLength); [h-NX
ROfV Y:,M
.#Z'CZO|
return nFileLength; ZL0k
} ^_3$f
5wh(Qdib
yx&}bu\
//保存下载信息（文件指针位置） /O$~)2^h
private void write_nPos() Q.7X3A8
{ ) ?kbHm
try{ mZ? jpnd
output = new DataOutputStream(new FileOutputStream(tmpFile)); B*3_m _a
output.writeInt(nStartPos.length); F=5vAv1
for(int i=0;i<nStartPos.length;i++) g\/|7:yB]
{ #DguV
// output.writeLong(nPos); 1I'}Uh*
output.writeLong(fileSplitterFetch.nStartPos); 7Dl^5q.|
output.writeLong(fileSplitterFetch.nEndPos); 'Kkp!eZQ~
} I]5){Q"S
output.close(); |0uqW1
} <_pLmYI
catch(IOException e){e.printStackTrace ();} {wt9/IlG1
catch(Exception e){e.printStackTrace ();} Gdx%#@/
} *L>usLh
|B$JX'_
*gGw/jA/
//读取保存的下载信息（文件指针位置） ^/Yk*Ny
private void read_nPos() -{JReplc
{ K iXD1Zpz
try{ _C1u}1hW#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E=S_1
int nCount = input.readInt(); sA: /!9
nStartPos = new long[nCount]; i=>`=. ~
nEndPos = new long[nCount]; pp*MHM)x|q
for(int i=0;i<nStartPos.length;i++) ? N]bFW"t|
{ A>F&b1
nStartPos = input.readLong(); X"g,QqDD
nEndPos = input.readLong(); :4X,5X7tW=
} wRwx((eb
input.close(); +kxk z"fP
} ]5`A8-Q@
catch(IOException e){e.printStackTrace ();} uQW[2f
catch(Exception e){e.printStackTrace ();} _}']h^@Z
} ;UX9Em
0L"uU3
yJqDB$0
private void processErrorCode(int nErrorCode) I 6<LKI/
{ cMy?&
System.err.println("Error Code : " + nErrorCode); _h=h43'3
} L7(.dO0C
d@cyQFX
3)&rj 7
//停止文件下载 i ^N}avO
public void siteStop() Cx(HsJ!,
{ {O!;cI~
bStop = true; r[kHVT8
for(int i=0;i<nStartPos.length;i++) !{uV-c-5,
fileSplitterFetch.splitterStop(); F3Vvqt*2
U;.cXU{
I|>IV
} ci(BPnQ
} [vY)y\W{
//负责部分文件的抓取 p"cY/2w:j
**FileSplitterFetch.java WwSyw?T
*/ @.`HvS
package NetFox; GLV`IkU %
G8^b9xoA+.
Pj8Vl)8~NV
import java.io.*; }gX4dv B
import java.net.*; 5/m*Lc+r
FEa%wS{
Mwj7*pxUh
public class FileSplitterFetch extends Thread { {Y]3t9!\
N;m62N
GBd mT-7
String sURL; //File URL &\/}.rF
long nStartPos; //File Snippet Start Position iHo0:J~
long nEndPos; //File Snippet End Position *;t_VlaZ
int nThreadID; //Thread's ID n1+J{EPH
boolean bDownOver = false; //Downing is over )5;|mV
boolean bStop = false; //Stop identical E*9W'e~=
FileAccessI fileAccessI = null; //File Access interface =`gFwH<
KHaYb5(a[
c1f`?i}.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Uf[Gs/!NV
{ 2PSv3?".
this.sURL = sURL; )MM(HS
this.nStartPos = nStart; )@.ODW;`
this.nEndPos = nEnd; uA%F0oM
nThreadID = id; XT==N-5,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Gn10)Uf8X
} A#79$[>w
N *n?hN
aMJ9U)wnK
public void run() $~A\l@xAG
{ e7U9"pk
while(nStartPos < nEndPos && !bStop) ?nR$>a`
{ }T=\hM
,}Ic($To
AlgVsE%Va
try{ VD=F{|^
URL url = new URL(sURL); n6INI~,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jLul:* L
httpConnection.setRequestProperty("User-Agent","NetFox"); u/?;J1z:
String sProperty = "bytes="+nStartPos+"-"; P(zquKm
httpConnection.setRequestProperty("RANGE",sProperty); B"RZpx
Utility.log(sProperty); iF+50d
1 7hXg"B
0L7^Vr)
InputStream input = httpConnection.getInputStream(); G{|FV m
//logResponseHead(httpConnection); jBd9 $`
:4238J8
."v&?o Ck]
byte[] b = new byte[1024]; ou&7v<)x4
int nRead; kca Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N%?8Bm~dP
{ umiD2BRZ
nStartPos += fileAccessI.write(b,0,nRead); hN:2(x
//if(nThreadID == 1) FkoN+\d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LGVGr
} Tj=g[)+K
GwlAEhP
cFG%Ew@
Utility.log("Thread " + nThreadID + " is over!"); K~z9b4a>
bDownOver = true; *icxK
//nPos = fileAccessI.write (b,0,nRead); rMUQh~a/
} `qbsDfq@
catch(Exception e){e.printStackTrace ();} Tq >?.bq9
} W3i X;-Z
} :cTwp K
Dr"F5Wbg
gB#$"mq,
//打印回应的头信息 y `w5u.'
public void logResponseHead(HttpURLConnection con) ;0++):30V
{ ;,LlOR
for(int i=1;;i++) `\S~;O
{ uwb>q"M
String header=con.getHeaderFieldKey(i); ?Wp{tB9N0
if(header!=null) noNL.%I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~7=w,+
Utility.log(header+" : "+con.getHeaderField(header)); Wv)2dD2I
else We#O'm
break; KY;E.D`
} W?auY_+P
} -zLxT
(z<&PP
#bLeK$
public void splitterStop() )kNyl@m
{ +xtR`Y"
bStop = true; s|&2QG0'7
} mh`VZQ@
v~>4c<eG
&+t,fwlM
} Fop"m/
K29KS)~;W
=zW.~(c{
/* CpICb9w
**FileAccess.java )<jT;cT!&
*//文件访问(定位，写) $PNIuC?=
package NetFox; kQm\;[R
import java.io.*; TXQY&7
Kth^WHL
#r)c@?T@j
public class FileAccessI implements Serializable{ EGyQhZ mO
j^Z3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bKH8/*Yk
RandomAccessFile oSavedFile; F/w!4,'<?5
long nPos; .Su9fjy%
'rdg
Nl1v*9_x
public FileAccessI() throws IOException Jk7[}Jc$
{ t1 .6+
this("",0); wBXgzd%L
} KArnNmJ9
eESJk14
}3!.e
public FileAccessI(String sName,long nPos) throws IOException PV%7m7=x
{ z|SLH<~
oSavedFile = new RandomAccessFile(sName,"rw"); R3$eq )
this.nPos = nPos; 2$? )VXtw
oSavedFile.seek(nPos); =lG5Kc{B
} 8f|
8ESBui3;
pOip$Z
public synchronized int write(byte[] b,int nStart,int nLen) [0}^w[
{ ,saf"Ed=
int n = -1; >c7fg^@
try{ C@L:m1fz
oSavedFile.write(b,nStart,nLen); ?H3xE=<X
n = nLen; _D(F[p|
} iffRGnN^e
catch(IOException e) "ND 7,rQ
{ t <#Yr%a
e.printStackTrace (); 8<uKzb(O:
} xFS`#1
dYJW`Q;j.|
eW+z@\d9Gz
return n; ZuF-$]oL&
} YXa^jFp
gKS0!U
jfHVXu^M
} hC8'6h
=2{^qvP
D{/GjFO
/* nQvv'%v0
**SiteInfoBean.java u*&wMR>Crf
*/ 7{XI^I:n
package NetFox; z@biX
I"9S
uV*&a~
public class SiteInfoBean { pXCmyLQ
8fJ- XFK$:
0*8[m+j1
private String sSiteURL; //Site's URL y:Qo:Z~
private String sFilePath; //Saved File's Path (3"V5r`*;
private String sFileName; //Saved File's Name /'p(X~X:l
private int nSplitter; //Count of Splited Downloading File 'LR5s[$j
}dE0WJcO
5"6Y=AuQ6
public SiteInfoBean() [:sV;37s
{//nSplitter的缺省值为5 $}7/mS@c
//default value of nSplitter is 5 -mG3#88*
this("","","",5); <D pi M`
} qV.*sdS>
+X0?bVT
Jpws1~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sL XQ)Ce
{ 4jj@"*^a
sSiteURL= sURL; k|nv[xY0
sFilePath = sPath; c ++tk4
sFileName = sName; .QzHHW4&0
this.nSplitter = nSpiltter; 2|Hq[c=~
RpR;1ktF>
QkwBw^'_5
} 7\K=8G
3j(GcR9
z6b!,lp
public String getSSiteURL() N%:QaCZKw
{ U*=ebZno
return sSiteURL; 9=~"^dp54%
} Y_)!U`>N?
/N7j5v(
{o4m3[C7=}
public void setSSiteURL(String value) `$7j:<c=
{ O!kBp(?]
sSiteURL = value; vWcU+GBZI
} TB4|dj-%
R-"A*/A 2
j}'spKxu
public String getSFilePath() $+)SW{7
{ ;zIAh[z
return sFilePath; u)MdFz
} B3]q*ERAo
NB;8 e>8
noC]&4b
public void setSFilePath(String value) E=3<F_3W
{ YUat}-S
sFilePath = value; |#Bz&T
} G@ XKE17
_K3?0<=4
NSUw7hnWvz
public String getSFileName() k/?5Fs!#
{ znzh$9tH
return sFileName; @S yGj#
} OW\r }
gh|TlvnA
m@R!o
public void setSFileName(String value) WrQe'ny
{ c%yhODq/
sFileName = value; %,E\8{I+
} PW x9CT
+;tXk
>&7K|$y.J
public int getNSplitter() (4LXoNT
{ F??})YX
return nSplitter; o nt8q8
} D$+9`
D$d8u=S
+6-c<m|
public void setNSplitter(int nCount) nxkbI:+t
{ H[UV]qO,
nSplitter = nCount; -uXf?sTV
} (;;%B=
} W~z 2Q so
+hI:5(_
Va"Q1 *"
/* fgK1+sW
**Utility.java Pk!RgoWF
*/ Tz[ck'k
package NetFox; [QEV6S]
\wEHYz
c"Ddw'?e
public class Utility { w5w,jD[
OOn{Wp
ov*?[Y7|~
public Utility() U}<5%"!;
{ E*'sk
sygxV
d _)5Ks}
} DJvmwFx
]1hW/!
//线程睡眠 "`qmeZ$rg
public static void sleep(int nSecond) D^8]+2r
{ S=B?bD_,c
try{ ,$s NfW
Thread.sleep(nSecond); M?l/_!QB
} z{Z4{&M
catch(Exception e) \ :To\6\Ri
{ .R'<v^H
e.printStackTrace (); ,RjE?M%
} )voJq\Y)%
} !_C*2+f
RC'4%++Nz
//日志 2wLnRP`*
public static void log(String sMsg) /.P9n9
{ 9.u}<m
System.err.println(sMsg); 4zyN>f|
} _ p%=RIR
uF,F<%d
"159Q
public static void log(int sMsg) wV8_O)[
{ 3m%oXT
System.err.println(sMsg); C+o1.#]JM
} j5\z7
} x7\b-EC
]!CMo+
O(x1Ja,&
/* }huj%Pnk)
**TestMethod.java N~H!6N W
*/ B'}h6ZH
package NetFox; 9U~fc U6
U )kl!
>T84NFdz+
public class TestMethod { Nz/PAs7g6
JBqL0H
U'~M(9uv:
public TestMethod() J5dwd,FQ
{ ///xx/weblogic60b2_win.exe NxY B)`~
try{ %8Eu{3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?APzb4f^W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); slUnB6@Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6z`l}<q
fileFetch.start(); ^m0nInH
} \f~m6j$D_
catch(Exception e){e.printStackTrace ();} tb$I8T
|wbXu:
Kk.a9uKI}
} Wo)$*?
Qa`+-Wu8
U{1%ldOJ%
public static void main(String[] args) xB5qX7*.
{ p>#sR4d>
new TestMethod(); Q1kZ+b&
} XLHi
} (KG2X
点击下载更多相关资料