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)); t~)4f.F:
} nE?:nJ|%E
for(int i=0;i<nEndPos.length-1;i++) WncHgz
{ /Dyig
nEndPos = nStartPos[i+1]; \Ui8gDJ8y5
} SL`; `//
nEndPos[nEndPos.length-1] = nFileLength; _\8E/4zh
} >5?c93?
} }2\Hg
,% 'r:@'
.JTRFk{W
//启动子线程 ^hr# 1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ui-Y`
for(int i=0;i<nStartPos.length;i++) 4=`1C-v?q
{ X$G:3uoN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V|F/ynJfA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \){_\{&
nStartPos,nEndPos,i); Pa#Jwo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X}5"ZLa7l
fileSplitterFetch.start(); Yakrsi/jV}
} UtC<TBr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \So)g)K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P[$idRS&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P.g./8N`z
nEndPos = " + nFileLength); Nq^o8q_
// fileSplitterFetch[nPos.length-1].start(); v~W;&{
qx9;"Ut
c<~DYe;;
//等待子线程结束 wAgVevE
//int count = 0; tk:nth
//是否结束while循环 j^v<rCzc(
boolean breakWhile = false; L_|iQwU%
gwsOw [;k
O/$41mK+!
while(!bStop) >|gXE>
{ O2yD{i#l*#
write_nPos(); wDSwcNS
Utility.sleep(500); NPFI^Uj#A
breakWhile = true; NH:Bdl3
9i lJ
8e ?9:VM]
for(int i=0;i<nStartPos.length;i++) TKbfZw
{ n5efHJU
if(!fileSplitterFetch.bDownOver) {5HQ=&
{ g;OR{
breakWhile = false; 44t;#6p@%>
break; |}:q@]dC#
} !6sR|c"~j
} PR AP~P&^
if(breakWhile) [3ggJcUgW>
break; K6)IBV;
I>w|80%%
[} d39
//count++; 9eE FX7
//if(count>4) :;hm^m]Y
// siteStop(); a;kiAJ'
} jsF5q~F
<Wj/A/
TEGg)\+D>
System.err.println("文件下载结束！"); Im};wJ&
} \}<J>R@
catch(Exception e){e.printStackTrace ();} bE=[P}E
} Jk:ZO|'Z
hOV5WO\
&B1!,joH~
//获得文件长度 %F$]v
public long getFileSize() h/y0Q~|/d
{ Fo5UG2E&
int nFileLength = -1; ACFEM9 [=
try{ F9(jx#J~t
URL url = new URL(siteInfoBean.getSSiteURL()); !}c\u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a*_&[
httpConnection.setRequestProperty("User-Agent","NetFox"); O-pH~E
Oml /;p
kp!(e0n
int responseCode=httpConnection.getResponseCode(); iCGHcN^3
if(responseCode>=400) !Htl e %
{ @Jlsx0i}}
processErrorCode(responseCode); P1]F0fR
return -2; //-2 represent access is error $]W*;MTI}
} &uV|Ie8@q
J-G)mvkv
cg_tJ^vrY
String sHeader; ^vzXT>t-M
;NAKU
;<6S\
for(int i=1;;i++) P]2 /}\f
{ Q84XmXm|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (y\.uPu!
//Utility.log(in.readLine()); _`laP5~
sHeader=httpConnection.getHeaderFieldKey(i); hv#LKyp%
if(sHeader!=null) ^)$T`
{ vfVF^ WOd
if(sHeader.equals("Content-Length")) )7AjRtb!/
{ e(OKE7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .lI.I
break; nJ1<8 p
} xk,1D
} RUut7[r
else p_fsEY
break; B4c;/W-
} 5nmE*(
} ;2MdvHhz1
catch(IOException e){e.printStackTrace ();} 8{7'w|/;.{
catch(Exception e){e.printStackTrace ();} ]/%CTD(O
UIZ9"Da
m1tc="j
Utility.log(nFileLength); dDA&\BuS
DGz}d,ie
@00&J~D
return nFileLength; j.V7`x
} +K2HMf'
7E?60^Tve
goD#2lg
//保存下载信息（文件指针位置） o?3C-A|
private void write_nPos() :Fh_Ya0
{ DIhV;[\
try{ e;"%h%'
output = new DataOutputStream(new FileOutputStream(tmpFile)); )IIWXN2A
output.writeInt(nStartPos.length); gy#G;9p
for(int i=0;i<nStartPos.length;i++) xyXVWd[
{ $z5C+K@
// output.writeLong(nPos); KEq48+j
output.writeLong(fileSplitterFetch.nStartPos); qV``' _=<
output.writeLong(fileSplitterFetch.nEndPos); Tv% Z|%*
} /"R{1
output.close(); +4D#Ht7
} \TYH7wXDP
catch(IOException e){e.printStackTrace ();} 9/R=_y-
catch(Exception e){e.printStackTrace ();} bZ+Hu~
} ws,VO*4
]*{tno
'X_%m~}N
//读取保存的下载信息（文件指针位置） \@^` G
private void read_nPos() ^~bAixH^k
{ <){J|O
try{ 92*"3)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "9y0]~
int nCount = input.readInt(); 7Fb!;W#X
nStartPos = new long[nCount]; E-?JHJloU
nEndPos = new long[nCount]; BG]|iHi
for(int i=0;i<nStartPos.length;i++) g\aq#QV
{ Xupwh5G2
nStartPos = input.readLong(); %kQ[zd^
nEndPos = input.readLong(); Dkg-y9
} 3Z%jx#
input.close(); WxtB:7J
} RTL@WI
catch(IOException e){e.printStackTrace ();} WtMDHfwqu\
catch(Exception e){e.printStackTrace ();} d#I; e
} 0F&(}`V
`2HNQiK'@
TLz>|gr
private void processErrorCode(int nErrorCode) id1gK(F8H
{ UGA``;f
System.err.println("Error Code : " + nErrorCode); i/,IG+4vI
} 2rS`ViicD
Wr4Ob*2iD
x!?$y_t
//停止文件下载 88DMD"$B
public void siteStop() uC 2{ Mmy
{ 0qN+W&H
bStop = true; rp!{QG
for(int i=0;i<nStartPos.length;i++) |W|RX3D
fileSplitterFetch.splitterStop(); D}nRH@<`
9t&m\J >8;
Z.U8d(
} ;W@
} !q^2| %
//负责部分文件的抓取 A$::|2~
**FileSplitterFetch.java h$$i@IO0
*/ >WY\P4)k
package NetFox; z3yAb"1Hg
,T+.xB;Q@
[|L~" BB
import java.io.*; v)v`896S`
import java.net.*; j[:Iu#VR
&W>%E!F
[-3x*?Ju
public class FileSplitterFetch extends Thread { }#`-mRaU
g+KuK`\N%
WiF6*]oI
String sURL; //File URL |'Ksy{lA
long nStartPos; //File Snippet Start Position nh/%0=S
long nEndPos; //File Snippet End Position _%PEv{H0.
int nThreadID; //Thread's ID 7qhX`$
boolean bDownOver = false; //Downing is over H\=S_b1wo
boolean bStop = false; //Stop identical -JXCO<~k
FileAccessI fileAccessI = null; //File Access interface 9Pdol!
;0O>$|kg
nSbcq>3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException " VSma
{ QbEb} Jt
this.sURL = sURL; e/<'HM T
this.nStartPos = nStart; KhNOxMZ
this.nEndPos = nEnd; JcW<<7R
nThreadID = id; Z$Vd8U;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2zbV9Bhq
} s-T#-raE
W7q!F
""_%u'7t5I
public void run() Z WhV"]w&
{ l9F]Lw
while(nStartPos < nEndPos && !bStop) `"eIzLc%o6
{ `it
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x:`"tJa
try{ N7dI}ju
URL url = new URL(sURL); kaNK@a=e|/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rSNaflYAr
httpConnection.setRequestProperty("User-Agent","NetFox"); RhSoD.Da
String sProperty = "bytes="+nStartPos+"-"; [?VkwFD0
httpConnection.setRequestProperty("RANGE",sProperty); 7DWHADr
Utility.log(sProperty); 42.y.LtZ
t ;bU#THM
f^@DuI
InputStream input = httpConnection.getInputStream(); kD_616
//logResponseHead(httpConnection); L9,O,f
k6^!G"
#CNK [y
byte[] b = new byte[1024]; jmn<gJ2Of
int nRead; #;s5=aH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pLsWy&G
{ pXoT@[}
nStartPos += fileAccessI.write(b,0,nRead); n_P2l<F~/x
//if(nThreadID == 1) I_iXu;UX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xC-&<s
} _{y4N0
e<HHgC#J
o@DlK`
Utility.log("Thread " + nThreadID + " is over!"); 5<h:kZ"S^g
bDownOver = true; ]E}eM@xdD
//nPos = fileAccessI.write (b,0,nRead); }\hz@G<
} p JM&R<i:
catch(Exception e){e.printStackTrace ();} _|s'0F/t
} {M P(*N
} )~ghb"K
a>BPK"K2
rFG_CC2
//打印回应的头信息 g66SCr}
public void logResponseHead(HttpURLConnection con) CP6xyXOlPB
{ ^;.&=3N,+
for(int i=1;;i++) \EQCR[7qu7
{ ]5:0.$5
String header=con.getHeaderFieldKey(i); 8\$u/(DX
if(header!=null) m 9.BU2.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L IRdWGQ4
Utility.log(header+" : "+con.getHeaderField(header)); 6"u"B-cz
else ,?`Zrxe[
break; 3s$vaV~(a
} 9<-7AN}Z
} L3'$"L.|u
Xx e07J~
>4]y)df5
public void splitterStop() [^eQGv[S
{ T6I$7F
bStop = true; raB',Vp
} +`l)W`zX
2HF_kYZ
Y3?)*kz%
} XSe\@t~&g
@Avve8S
d3tr9B
/* @$!rgLyL[
**FileAccess.java sJ5Ws%q
*//文件访问(定位，写) J6RzN'j
package NetFox; ,^uQw/
import java.io.*; Q> J9M`a
#Mrc!pT]xy
V~"-\@
public class FileAccessI implements Serializable{ J @^Ypq
#B!<gA$/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tlpTq\;
RandomAccessFile oSavedFile; JbXd9AMh2
long nPos; ^H~g7&f9?N
ISi^BFU
c,FZ{O@
public FileAccessI() throws IOException 0artR~*}
{ g&?{^4t]
this("",0); l$g \t]
} QpiA~4
Oe"nNvu/
(svKq(X
public FileAccessI(String sName,long nPos) throws IOException .r\|9 *j<
{ -X_dY>>s
oSavedFile = new RandomAccessFile(sName,"rw"); 9|qzFmE#
this.nPos = nPos; rIQ%X`Y
oSavedFile.seek(nPos); D/bF
} ,qT+Vqpr{
f yhBfA:u
^!*nhs%
public synchronized int write(byte[] b,int nStart,int nLen) 8\Kpc;zb
{ n'qWS/0U=
int n = -1; BKk+<#Ti
try{ >Q[3t79^
oSavedFile.write(b,nStart,nLen); ^:Fj+d
n = nLen; F-%Hw
} -SUK[<=X
catch(IOException e) 6}>CPi#
{ i>%A0.9
e.printStackTrace (); (DY&{vudF
} ]\(Ho
\IO<V9^L
AfvIzsT0
return n; sny$[!)
} BD?u|Fd,i:
- `{T?
}j;G`mV2
} c;.jo?RR2
4n6t(/]b<
,C0D|q4/!.
/* 2U@:.S'K
**SiteInfoBean.java =hi{J M
*/ qijQRxS
package NetFox; ,Rdw]O
dheobD
e5#?@}?
public class SiteInfoBean { IZ<Et/3H
=B0AG9Fz
U88gJ[$
private String sSiteURL; //Site's URL 3@wio[
private String sFilePath; //Saved File's Path i'p6#
private String sFileName; //Saved File's Name z>z9xG'
private int nSplitter; //Count of Splited Downloading File :pvB}RYD
=d#(n M*
[,sm]/Xlc
public SiteInfoBean() jr/IU=u*v
{//nSplitter的缺省值为5 "P yG;N!W
//default value of nSplitter is 5 wWQt
this("","","",5); 1xjWD30
} z-_$P)[c
Scfe6+\EW
</!GU*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E?S
{ ^j7>Ul,
sSiteURL= sURL; *JF7 B
sFilePath = sPath; `Gh J)WA<
sFileName = sName; pU1miA '
this.nSplitter = nSpiltter; B["jndyr
ca<OG;R^
DdqE6qE
} xM=?ES
Jk;dtLL}4
QXEz[R
public String getSSiteURL() Y2[ik<
{ HT7I~]W
return sSiteURL; -f["1-A
} )zkr[;j~`
r-o+NV
@cc}[Uw4B
public void setSSiteURL(String value) lJdrrR)wg
{ ai"N;1/1O|
sSiteURL = value; q\xsXM
} Zs2;VW4RW
]z8Th5a?o
'&/~Sh$%
public String getSFilePath() |_OoD9,M
{ %LBf'iA
return sFilePath; }kSP p
} UJ><B"
o:`^1
`=%G&_3_<
public void setSFilePath(String value) PLq]\y
{ o)+C4f[G4
sFilePath = value; AnoA5H
} |h& q
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mYbu1542'n
public String getSFileName() wRg[Mu,Q5
{ e!vWGnY
return sFileName; )JY#8,{w
} d2fiPI7lg
;@qQ^!g2
f.0HIc
public void setSFileName(String value) is=x6G*r
{ ET(/h/r
sFileName = value; cZ3A~dTOR
} A3|2;4t
mbHMy[R
9Zr6 KA{
public int getNSplitter() ;H9 W:_ahE
{ |XmzqX%
return nSplitter; 0-p %.}GE
} 5t|$Yt[
LI>Bl
<?%49
public void setNSplitter(int nCount) :XOjS[wBm
{ %4})_h?j
nSplitter = nCount; KQ0f2?
} udPLWrPF\
} pm2]
f#-\*
B<ZCuVWH:
/* D;z!C ys
**Utility.java iD/+#UTY
*/ O"1HO[
package NetFox; !Wj`U$];
jOZ>^5}
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public class Utility { AoY!f'Z
W6):IW(E
<pM6fI6BD
public Utility() :;\xyy}A
{ Gp=V%w\FDW
fi%lN_Ev?
>^SQrB
} BZIU@^Q_Y[
GC|V>| tz#
//线程睡眠 iFZ.a.NDc
public static void sleep(int nSecond) Ym6v4k!@O
{ _Td#C1g3
try{ pcQgWjfS
Thread.sleep(nSecond); NTSIClm}U
} qcge#S>
catch(Exception e) >8&fFq
{ N*\ri0
e.printStackTrace (); l;@bs
} PP]7_h^2
} C3~O6<,Jh
&UO/p/a
//日志 93=?^
public static void log(String sMsg) V9cj
{ _|{Z850AS
System.err.println(sMsg); 5g.Kyj|
} g ;XK3R
GyVuQ51
g?*D)WU
public static void log(int sMsg) (B%[NC6
{ {XV'C@B
System.err.println(sMsg); !_oR/)
} uX%$3k
} . BX*C
TaF;PGjVw
QB !%
/* <U8w#dc
**TestMethod.java 2*] [M,L0c
*/ q s:TR
package NetFox; NC iBn>=:
SiJ{
6PC?*^v
public class TestMethod { wOLV?Vk
"U$](k.<VA
%*RZxR):
public TestMethod() h92KU
{ ///xx/weblogic60b2_win.exe A`"?~_pHC
try{ $GHi9aj_P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AUES;2WL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8L]Cc!~
SiteFileFetch fileFetch = new SiteFileFetch(bean); :B\$7+$v
fileFetch.start(); 7r2p+LP[
} #w8.aNU+]
catch(Exception e){e.printStackTrace ();} 50a';!H
=(~ZmB\
/82E[P"}6R
} ~Q5]?ZNX
[)il_3t
J*m7 d4^
public static void main(String[] args) igEqty!.
{ 0uIBaW3s
new TestMethod(); &|' NDcp
} irP*:QM
} G[u{! 2RS
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