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)); E5{)d~q
} z]AS@}wWqg
for(int i=0;i<nEndPos.length-1;i++) X)OP316yx
{ n0pe7/Ai
nEndPos = nStartPos[i+1]; [i1D~rCcn
} 7F:;3c
nEndPos[nEndPos.length-1] = nFileLength; ;@ X
} 1I_q3{
} ^)l@7XxD
@|Bp'`j%J
qXGLv4c`Q
//启动子线程 )\Q|}JV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H>iZVE
for(int i=0;i<nStartPos.length;i++) nV*sdSt
{ iQC&d_#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *8H;KGe=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9z/_`Xd_
nStartPos,nEndPos,i); 3uG5b8?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jgw'MpQm{
fileSplitterFetch.start(); ]?$y}
} KocXSh U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >%dAqYi $
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); RpP[ymMZJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {; cB?II
nEndPos = " + nFileLength); vXQmEIm
// fileSplitterFetch[nPos.length-1].start(); X]"OW
C*e[CP@u
+/86w59
//等待子线程结束 4S9, tc&
//int count = 0; ,nRwwFd.
//是否结束while循环 l]y%cJ~$'D
boolean breakWhile = false; aB6LAb2z;T
91d`LsP
V9+"CB^
while(!bStop) Sc3M#qm_
{ E(+wl
write_nPos(); ,<r3Z$G
Utility.sleep(500); psy(]Pf
breakWhile = true; Pt0}9Q
<?Izfl6
~<[5uZIo
for(int i=0;i<nStartPos.length;i++) KqUSTR1e[
{ @/NZ>.
if(!fileSplitterFetch.bDownOver) i=H>D
{ A""*vqA
breakWhile = false; QN&^LaB<T
break; R&_\&:4f
} 9OT4jAm
} )TG0m= *
if(breakWhile) LNxE-Dp
break; ]l7\Zq
)u/ ^aK53^
AaC1||?R
//count++; xjq7%R_,
//if(count>4) eEGcio}_I9
// siteStop(); ,W8Iabi^
} C*6)Ut '
y&=19A#
"M0l;
System.err.println("文件下载结束！"); k+r9h'd
} cPaWJ+c
catch(Exception e){e.printStackTrace ();} lrX0c$)
} )u)$ `a
a:^Gr%
}cK~=@7tK
//获得文件长度 8|qB1fB
public long getFileSize() C5PBfn<j
{ nC.2./OwMf
int nFileLength = -1; !v4j`A;%
try{ =*:_swd
URL url = new URL(siteInfoBean.getSSiteURL()); yO,`"Dc_0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~TFYlV
httpConnection.setRequestProperty("User-Agent","NetFox"); #Q7x:,f
c[RLYu
J[Yg]6
int responseCode=httpConnection.getResponseCode(); 5h=TV
if(responseCode>=400) 4zfRD`;
{ !a&SB*%^I3
processErrorCode(responseCode); qM!f
return -2; //-2 represent access is error z>p`!-'ID
} n$|c{2]=
>"<k8wn
MAD}Tv\S7
String sHeader; CndgfOF
u6Qf*_-K
-S%q!%}u
for(int i=1;;i++) u!3]RGJ
{ 5+/b$mHZX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YyJ{
//Utility.log(in.readLine()); "(\) &G
sHeader=httpConnection.getHeaderFieldKey(i); ZecvjbnVY
if(sHeader!=null) zIm_7\e
{ M|({ 4C
if(sHeader.equals("Content-Length")) 9ze|s^
{ G>w?9:V}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z1'FmwT
break; z'oiyXEE3
} 2Jo~m_
} o!toO&=
else %t`SSW7I
break; {s8U7rmML
} bH\C5zt6(
} mYh5#E41J
catch(IOException e){e.printStackTrace ();} %`?;V;{=
catch(Exception e){e.printStackTrace ();} ?)' 2l6
9XoQO9*Q
^K.u ~p
Utility.log(nFileLength); phgexAq
6vgBqn[
5`E`Kb+@
return nFileLength; '{0[&i*
} &(1H!
a%T -Z.rd
gM3]%L_
//保存下载信息（文件指针位置） /$9BPjO{
private void write_nPos() %/y`<lJz(
{ Z6^QB@moj
try{ @1qdd~B}
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9:%n=URd
output.writeInt(nStartPos.length); `D)Lzm R
for(int i=0;i<nStartPos.length;i++) ,]Ro',A&
{ }{5mH:
// output.writeLong(nPos); wMz-U- z
output.writeLong(fileSplitterFetch.nStartPos); v0Ai!#
output.writeLong(fileSplitterFetch.nEndPos); iIsEQh
} I%9bPQ
output.close(); 3T|Y}
} Ts(t:^
catch(IOException e){e.printStackTrace ();} j1puB
catch(Exception e){e.printStackTrace ();} -Aa]aDAz68
} /Fe:h>6
e2k4[V
79SqYe=&uy
//读取保存的下载信息（文件指针位置） @n7t?9Bx
private void read_nPos() L\}Pzxn
{ s!#HZK
try{ zb5N,!%r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xb]=:x(
int nCount = input.readInt(); I(]BMMj
nStartPos = new long[nCount]; tx0Go'{
nEndPos = new long[nCount]; o3n3URu\
for(int i=0;i<nStartPos.length;i++) dU]i-NF
{ K4!P'
nStartPos = input.readLong(); P3iA(3I24<
nEndPos = input.readLong(); X"[dQ_o
} k7^R,.c@
input.close(); !TP6=ks
} ohrw\<xsu
catch(IOException e){e.printStackTrace ();} LY-lTr@A^
catch(Exception e){e.printStackTrace ();} }iilzE4oH#
} "v(G7*2
a`H\-G
B(j02<-
private void processErrorCode(int nErrorCode) +7Yu^&
{ hCzjC|EO~
System.err.println("Error Code : " + nErrorCode); #(%t*"IY;
} )n7|?@5U
l80bHp=
O)`fvpVU
//停止文件下载 [N)#/6j
public void siteStop() YP[LQ>
{ ajn-KG!A
bStop = true; % f2<U;ff
for(int i=0;i<nStartPos.length;i++) [}>#YPZ
fileSplitterFetch.splitterStop(); F:%^&%\
M h`CP
k$C"xg2
} Dp*:Q){>E
} 8q?;2w\l
//负责部分文件的抓取 >']+OrQH
**FileSplitterFetch.java C"w,('~@kW
*/ GDF{Lf)/v
package NetFox; U1l0Uke
$ye^uu;Z
xXF2"+
import java.io.*; (NX)oP
import java.net.*; ]}Pl%.
[ S5bj]D
hwiKOP
public class FileSplitterFetch extends Thread { HOE2*4r
ibvJWg
{G]?{c)"
String sURL; //File URL Bwjg#1E
long nStartPos; //File Snippet Start Position tNU-2r
long nEndPos; //File Snippet End Position y-'" >
int nThreadID; //Thread's ID #wF1
boolean bDownOver = false; //Downing is over Dy su{rL
boolean bStop = false; //Stop identical /Zc#j^_
FileAccessI fileAccessI = null; //File Access interface 2s 7mI'
e1Ob!N-
MRQZIi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M Hg6PQIB
{ huz86CO
this.sURL = sURL; [*Q-nZ/L
this.nStartPos = nStart; ! ,@ZQS
this.nEndPos = nEnd; UxyY<H~Wx
nThreadID = id; dY8(nQG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _R)&k%i}
} Vt'L1Wr0v
lr WLN
<P1rqM9^
public void run() <"?*zx&
{ qU#$2
while(nStartPos < nEndPos && !bStop) G*B$%?n
{ GR<c=
c<?[d!vI
6*Zj]is
try{ ! ao6e
URL url = new URL(sURL); ~ FGe~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D}w<84qX
httpConnection.setRequestProperty("User-Agent","NetFox"); n12UBvc}%
String sProperty = "bytes="+nStartPos+"-"; a5a1'IVq
httpConnection.setRequestProperty("RANGE",sProperty); !i^]UN
Utility.log(sProperty); }qAVN
L1wZU,o
P.cO6+jGR
InputStream input = httpConnection.getInputStream(); H'EY)s Hi
//logResponseHead(httpConnection); ZRnL_z~
pYt/378w
QQFf5^
byte[] b = new byte[1024]; SG:bM7*1'
int nRead; e2c1pgs&+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {b1UX9y
{ c` , 2h#
nStartPos += fileAccessI.write(b,0,nRead); FI8k;4|V
//if(nThreadID == 1) n$4|PO$X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <c+K3P'3?
} X8b|]Nr
[SkKz>rC
qgx?"$ Z
Utility.log("Thread " + nThreadID + " is over!"); :6Pnie
bDownOver = true; =NZ[${7mq
//nPos = fileAccessI.write (b,0,nRead); D<t~e$H
} 0z7L+2#b^
catch(Exception e){e.printStackTrace ();} `B:"6nW6
} o-z &7@3Hu
} P? (vW&B
3;-^YG
@DuK#W"E u
//打印回应的头信息 03([@d6<E
public void logResponseHead(HttpURLConnection con) mRwT_(;t
{ $w)~xE5;
for(int i=1;;i++) ;#&fgj
{ -f9]v9|l
String header=con.getHeaderFieldKey(i); UQI f}iR
if(header!=null) o>F*Itr{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OQScW2a&
Utility.log(header+" : "+con.getHeaderField(header)); Q`A6(y/s?
else @*(4dt:V
break; OP%?dh]
} T6Ctf#
} 3?.1nGu
s]H^wrg&
xx }GOY.J
public void splitterStop() R^%e1KO]
{ +}aC-&
bStop = true; /syVGmS'M
} D. Kqc
6;+jIkkD)
0/ !,Dn
} LnFWA0y
J[@um:
*5OCqU+g
/* Cqxv"NN
**FileAccess.java +@<KC
*//文件访问(定位，写) JYm7@gx
package NetFox; gsPl _
import java.io.*; UXH"si:
P=`1rjPE
_<zfQZai
public class FileAccessI implements Serializable{ %}&(h/= e
lw[e*q{s.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R-rCh.
RandomAccessFile oSavedFile; Wto;bd
long nPos; 33K*qaRAD
+}@8p[`)
J!TBREK
public FileAccessI() throws IOException .A6lj).:
{ tmJgm5v
this("",0); WR#0<cz(
} PB53myDQ
XIAeCU
Quzo8u
public FileAccessI(String sName,long nPos) throws IOException T9syo/(
{ 3s*(uS(
oSavedFile = new RandomAccessFile(sName,"rw"); W3rl^M=r
this.nPos = nPos; eZLMP
oSavedFile.seek(nPos); QI}E4-s8
} U# JIs
wO.iKX;
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public synchronized int write(byte[] b,int nStart,int nLen) %gd(wzco
{ mC[UXN/
int n = -1; -*a?<ES`
try{ MCc$TttaVz
oSavedFile.write(b,nStart,nLen); @5VV|Wt=
n = nLen; <rIz Z'D
} /6+NU^
catch(IOException e) @|\R}k%(
{ Q_p[kKH
e.printStackTrace (); ?_g1*@pA
} hhI)' $
jrMe G.e=D
:+rUBYWx
return n; O+~ 7l?o
} 'ZP)cI:+X
YB,t0%vTJw
Sw[{JB;y,
} ,Hn^z<f
89~ =eY
|=dC )Azs
/* D@oCP =m<
**SiteInfoBean.java {ZsdLF#
*/ 1HT_
package NetFox; E?)656F[
mQ~:Y
W# US#<9Y
public class SiteInfoBean { Te,$M3|
9QC.TG@
-&2B@]]
private String sSiteURL; //Site's URL i38[hQR9a
private String sFilePath; //Saved File's Path [KJ q
private String sFileName; //Saved File's Name q,>?QBct*
private int nSplitter; //Count of Splited Downloading File YDC&u8
ZD>a>]
TX [%(ft
public SiteInfoBean() qMYe{{r
{//nSplitter的缺省值为5 S9| a$3K'
//default value of nSplitter is 5 6Jz^
this("","","",5); 9uk<&nqx
} \]4v_!
]3iH[,KU3
Jc6R{C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?.=}pAub
{ |JF@6
sSiteURL= sURL; e8=YGx^o`
sFilePath = sPath; ~lAKJs#{
sFileName = sName; M~Ttb29{
this.nSplitter = nSpiltter; Cq)IayD@
Ro(Zmk\t
(la[KqqCO
} U_GgCI)
rQ`i8GF
l^MzN
public String getSSiteURL() .Dg*\ h
{ ~]C%/gEh
return sSiteURL; x#.C4O09
} V5F%_,No
UBv@+\Y8m
v *-0M
public void setSSiteURL(String value) @%ip7Y]e
{ \!]hU%Un
sSiteURL = value; kX`[Y@nUN
} j=?'4sF
SMH<'F7i
2{Vcb
public String getSFilePath() M$4[)6Y
{ }Z-Z|G)#
return sFilePath; X1{[}!
} Cqii}
RwI[R)k
gD`>Twa&6
public void setSFilePath(String value) WYB{% yf
{ Isy'{-H
sFilePath = value; 7{@l%jx][
} ($w@Z/;
0& >H^
SP*fv`
public String getSFileName() v3d&*I
{ ".^VI2T
return sFileName; _A13[Mt3
} xL|;VyD
DGW+>\G
NA3\
public void setSFileName(String value) osARA3\Xt
{ tZ`Ts}\e
sFileName = value; L(T12s
} <JMcIV837
bV8g|l-4(
css64WX^0c
public int getNSplitter() 3>E%e!D%
{ &k-Vcrcz
return nSplitter; W[EKD 7
} 9O{b]=>wq
l3Njq^T
J^R=dT!
public void setNSplitter(int nCount) ~/^5) g_
{ _Z5Mw+=19
nSplitter = nCount; \`V;z~@iA
} #mize
} {7TlN.(
-7J|l
^7zu<lX
/* }Sy=My89r
**Utility.java n -(
*/ Hbv6_H
package NetFox; qW:HNEiir
T91moRv
K\"R&{+=
public class Utility { u:0aM}9A
lL1k.&|5m
]Q]W5WDe:
public Utility() f&v9Q97=
{ "-@[R
AJ#Nenmj
241*!
} 6aM*:>C"
~4"qV_M
//线程睡眠 W9NX=gE4
public static void sleep(int nSecond) Xpzfm7CB/
{ vfVj=DYj
try{ Ft}@1w5
Thread.sleep(nSecond); g}@OUG"D
} w$JvB5O
catch(Exception e) 3R+|5Uq8~
{ D!7`CH+
e.printStackTrace (); MEB it
} >/|q:b^2r
} Lemui)
~69&6C1Ch
//日志 J2:y6kGj>
public static void log(String sMsg) '7O3/GDK
{ 13taFVdU
System.err.println(sMsg); <[w=TdCPs
} 6}r`/?"A1
T=ev[ mS
g+z1
public static void log(int sMsg) eM8}X[
{ <)1qt 9
System.err.println(sMsg); 3Z1CWzq(
} O({2ivX
} >y"+ -7V)
4EY)!?;
h$2</J"
/* 0Vx.nUQ
**TestMethod.java nr<4M0tIp
*/ ]q4rlT.i
package NetFox; Dh=9Gns9
YPxM<Gfa8
.SWlp2!M5
public class TestMethod { _*f`iu:`
(!:,+*YY
=i[\-
public TestMethod() q.;u?,|E/
{ ///xx/weblogic60b2_win.exe s7F.sg
try{ 4t=G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hm*/C4B`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RCpR3iC2
SiteFileFetch fileFetch = new SiteFileFetch(bean); *WuID2cOI
fileFetch.start(); #{;k{~;PF
} E 7{U|\
catch(Exception e){e.printStackTrace ();} ')cMiX\v
NCDvobYJ
u ,KD4{!
} tS6qWtE
,5h)x"s
-Fe?R*-g
public static void main(String[] args) )P sY($ &
{ jWA(C;W
new TestMethod(); 'd9INz.
} X9V*UXTc
} $|@ (
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