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)); '&gUAt
} j\Fbi3H
for(int i=0;i<nEndPos.length-1;i++) ZD$I-33W
{ BtJF1#f
nEndPos = nStartPos[i+1]; l+`CgYo
} ; +Ie<oW
nEndPos[nEndPos.length-1] = nFileLength; @8:c3(!
} =KnHa.%
} s-&i!d
(tzAUrC
4 BNbS|?vV
//启动子线程 &#~U1: 0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u`-:'@4
for(int i=0;i<nStartPos.length;i++) %)^0NQv
{ 1. Q"<[M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bZQ_j#{$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i !SN"SY
nStartPos,nEndPos,i); *>o@EUArN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u+jx3aP:
fileSplitterFetch.start(); ~+RrL,t#
} xBw ua;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t)(>E'X x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8jLO-^X<<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s>>lf&7
nEndPos = " + nFileLength); ,d=Dicaz
// fileSplitterFetch[nPos.length-1].start(); b+CvA(*
gKPqU@$*
Zyz)`>cB
//等待子线程结束 k9\n='OI
//int count = 0; f|yq~3x)
//是否结束while循环 3zM>2)T-
boolean breakWhile = false; /wHfc[b>
ZQ_~ L!ot
dGR #l)
while(!bStop) IY(;:#l
{ (51;cj>J
write_nPos(); IUh)g1u41O
Utility.sleep(500); n.P$E
breakWhile = true; Ye>+
)$2h:dw_
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for(int i=0;i<nStartPos.length;i++) . vea[
{ -#AO4xpI
if(!fileSplitterFetch.bDownOver) 3[m~6Ys
{ 4'`*Sce}
breakWhile = false; |qq29dS?
break; {UhpN"'"n
} 4&`d$K
} {?IUf~<
if(breakWhile) bGB5]%v,
break; zn\$6'"
).$kp2IN
2QIo|$
//count++; VZA>ErB
//if(count>4) FvBnmYnW
// siteStop(); %-NG eN8
} <bBgevL+_K
GIUyW
L7.LFWq$S
System.err.println("文件下载结束！"); ]jP0Z#
} v #Q(g/^
catch(Exception e){e.printStackTrace ();} B :1r;8{j
} \&Oc}]
]#$rTWMl'
0Jm)2@
//获得文件长度 "LVN:|!
public long getFileSize() +n<;);h
{ 45Q#6BtE
int nFileLength = -1; 0:>C v<N
try{ Yp9%u9tNq
URL url = new URL(siteInfoBean.getSSiteURL()); _qS4Ns/4s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .OF2O}
httpConnection.setRequestProperty("User-Agent","NetFox"); uF-Rl## >
UTuOean ]'
62/tg*)
int responseCode=httpConnection.getResponseCode(); )7N$lY<
if(responseCode>=400) B]cV|S|
{ 5U JMiwP{
processErrorCode(responseCode); <d3N2
return -2; //-2 represent access is error (_~Dyvo
} "eKM<S
BH?fFe&J:`
K%>3ev=y.s
String sHeader; 1f5;^T I
*3!ixDX[r
4=hz4(5a
for(int i=1;;i++) YR68'Sft[
{ GG`;c?d@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =xHzhh
//Utility.log(in.readLine()); 7C^W<SUo
sHeader=httpConnection.getHeaderFieldKey(i); '\B!1B>T
if(sHeader!=null) +}!FP3KgT
{ AaJnRtBS~
if(sHeader.equals("Content-Length")) xy<)zKp
{ \F),SL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _~E_#cNn
break; _VAX~Y]
} ltG|#(
} k|_LF[*Z
else ^9*Jz{e
break; SV_b(wP9
} )'t&LWS~
} NiH.Pv)Oa'
catch(IOException e){e.printStackTrace ();} 7.1FRxS
catch(Exception e){e.printStackTrace ();} )m$i``*<
C]%}L%,
o_%gFV[q
Utility.log(nFileLength); 'tzN.p1O
Q!}LtR$
G!m;J8#m(
return nFileLength; `v1~nNoY
} ndB*^nT
>U'gQS?\]
JAcNjzL
//保存下载信息（文件指针位置） g2&P
private void write_nPos() U10:@Wzh
{ H=7Nh6v
try{ RB/;qdqR
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2o9IP>#u
output.writeInt(nStartPos.length); D,;6$Pvg^
for(int i=0;i<nStartPos.length;i++) G_n~1?
{ }h`ddo
// output.writeLong(nPos); bjGQ04da
output.writeLong(fileSplitterFetch.nStartPos); 1 gx(L*y,
output.writeLong(fileSplitterFetch.nEndPos); {'eF;!!Dy
} 7W\aX*]
output.close(); m^ [VM&%
} S?LUSb
catch(IOException e){e.printStackTrace ();} iQ_^MzA
catch(Exception e){e.printStackTrace ();} Fo[=Dh*AqU
} !3Me 6&$O
8qQrJFm|3*
+%RB&:K7,
//读取保存的下载信息（文件指针位置） q|7$@H^*
private void read_nPos() ]k.'~Syz
{ QDJ:LJz\
try{ w`r)B`!g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1:d,8
int nCount = input.readInt(); :s'hXo
nStartPos = new long[nCount]; H;rLU9b
nEndPos = new long[nCount]; 5X"WgR;
for(int i=0;i<nStartPos.length;i++) 23WlUM
{ kv'gs+,e
nStartPos = input.readLong(); (J/!9NS:
nEndPos = input.readLong(); R?GF,s<j
} #^&.*'z%z
input.close(); YO^iEI.
} @jevY81)
catch(IOException e){e.printStackTrace ();} GjvTYg~
catch(Exception e){e.printStackTrace ();} Sk&l8"
} ZRo-=/1
2k3yf_N
meNz0ve
private void processErrorCode(int nErrorCode) `di/nv)
{ BY^5z<^.
System.err.println("Error Code : " + nErrorCode); O/2Jz
} i7(\i2_P
vAp?Zl?g
-$m?ShDd
//停止文件下载 ^L;k
public void siteStop() Q.Ljz Z
{ i@XFnt
bStop = true; 5!)_"u3
for(int i=0;i<nStartPos.length;i++) oc3}L^aD
fileSplitterFetch.splitterStop(); (N25.}8Y
'=eE6=m^K
<FFaaGiE>
} @:"GgkyDl#
} koAM",5D
//负责部分文件的抓取 jIs2R3B
**FileSplitterFetch.java y?s8UEC
*/ mjz<,s`D
package NetFox; '+{dr\nJ
l]o)KM<
6C|]Fm
import java.io.*; SQd`xbIuL
import java.net.*; iNAaTU
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Bpw<{U
public class FileSplitterFetch extends Thread { Rr>h8Ni <
hPHrq{YZ
Du2v,n5@
String sURL; //File URL !HP/`R
long nStartPos; //File Snippet Start Position vAMr&[
long nEndPos; //File Snippet End Position jL[ hB
int nThreadID; //Thread's ID J6Q}a7I#
boolean bDownOver = false; //Downing is over DfQD!}=
boolean bStop = false; //Stop identical az2CFd^M
FileAccessI fileAccessI = null; //File Access interface 8fwM)DKS
.xp|w^
Ew kZzVuX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t846:Z%[
{ a:3f>0_t
this.sURL = sURL; ;c_pa0L
this.nStartPos = nStart; w+0Ch1$
this.nEndPos = nEnd; )4P5i b
nThreadID = id; zsx12b^w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f{DcR"
} \!tS|h
Lx"a#rZ
4{r_EV[(
public void run() %g>{m2o
{ PNbs7f
while(nStartPos < nEndPos && !bStop) f1RfNiW.
{ !B3lsXLSY
dIR6dI
q|A-h'
try{ 3[jk}2R';p
URL url = new URL(sURL); D@ji1$K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iY2%_b!5
httpConnection.setRequestProperty("User-Agent","NetFox"); Mwdw7MZ"S
String sProperty = "bytes="+nStartPos+"-"; nd]AvVS
httpConnection.setRequestProperty("RANGE",sProperty); XTZI!
Utility.log(sProperty); V!SB9t`E
(1vmtg.O
-0)So
InputStream input = httpConnection.getInputStream(); LEJ7.82
//logResponseHead(httpConnection); DvuL1MeKo
IrRn@15,
adJoT-8P6
byte[] b = new byte[1024]; 2rw<]Ce
int nRead; Wsr #YNhx|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "Jp6EL%
{ 2Z-BZuK6p
nStartPos += fileAccessI.write(b,0,nRead); 3o'SY@'W
//if(nThreadID == 1) rGZ@pO2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IP1|$b}sq
} C3%,pDh
Te{L@sj
^j2:fJOU#
Utility.log("Thread " + nThreadID + " is over!"); +M\*C#
bDownOver = true; .~5cNu'#m
//nPos = fileAccessI.write (b,0,nRead); tc{23Rf%
} b'N"?W^YQ
catch(Exception e){e.printStackTrace ();} aNW&ib
} P-~Avb
} *TuoC5
azB~>#H~
n^/,>7J
//打印回应的头信息 b)u9#%Q
public void logResponseHead(HttpURLConnection con) d]e`t"Aj
{ <C4^Vem
for(int i=1;;i++) l!ye\
{ is}Fy>9i
String header=con.getHeaderFieldKey(i); v]*W*;
if(header!=null) XEZ6%Q_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tS2lex%
Utility.log(header+" : "+con.getHeaderField(header)); 8IC((
else _<.R\rX&
break; e_6 i896
} f|VP_o<
} ,ASY &J5)7
j.CC.[$g
YA^9, q6u?
public void splitterStop() N13 <!QQ
{ CWkm\=
bStop = true; No[xf9>t
} &F#X0h/m=
bi^LpyEn
A|>a Gy
} wCvD4C.WH
kX1hcAa
5<w0*~Zd~
/* 33Mr9Doon
**FileAccess.java 4 qW)R{%
*//文件访问(定位，写) n?,fF(
package NetFox; 9Zrn(D
import java.io.*; .^kTb2$X
_k+Bj.L
*pasI.2s#
public class FileAccessI implements Serializable{ 6-X7C9`C
N&>D/Z;"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QW2% Gv:
RandomAccessFile oSavedFile; \iVYhl
long nPos; kLD)<D
R4qk/@]t
2N,*S
public FileAccessI() throws IOException Ar'5kPzY>
{ d&'6l"${
this("",0); ]c5GG!E-g
} xUrfH$$!`
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Vfw$>og!
public FileAccessI(String sName,long nPos) throws IOException f:utw T
{ E_yh9lk
oSavedFile = new RandomAccessFile(sName,"rw"); &FanD
this.nPos = nPos; ?y04g u6p
oSavedFile.seek(nPos); :!A@B.E
} $K G?d>wx
OQsH,'
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public synchronized int write(byte[] b,int nStart,int nLen) 3> fuH'=
{ ja>Tnfu
int n = -1; [D?E\Nkk
try{ er<~dqZ}]
oSavedFile.write(b,nStart,nLen); (Pu*[STTT
n = nLen; G/`_$ c
} tIvtiN6[|l
catch(IOException e) da<1,hF
{ (^Ln|3iz
e.printStackTrace (); l;;:3:
} W.CIyGK
>3Y&jsh<
Je*gMq:D
return n; *LhR$(F(
} )i>KYg w
4i19HD_
5y~[2jB:
} UmJg-~
C'$U1%: j
N!va12
/* G dooy~cn
**SiteInfoBean.java AUq?<Vg\
*/ /;>EyWW
package NetFox; 6$Dbeb
#QB`'2)vw
2KX *x_-
public class SiteInfoBean { }$UFc1He\J
I'j?T.
/za,&7sf
private String sSiteURL; //Site's URL oc?VAF
private String sFilePath; //Saved File's Path u/zfx;K
private String sFileName; //Saved File's Name ~& l`"
private int nSplitter; //Count of Splited Downloading File 3A9|{Vaz+6
qjFgy)qV
aD:+,MZ
public SiteInfoBean() bd9c/>&
{//nSplitter的缺省值为5 s0h)~z
//default value of nSplitter is 5 0'<S7?~|
this("","","",5); qnlj~]NV
} $ S49v
8BN'fWl&E
-_}EQ9Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?\yo~=N^
{ xWMMHIu
sSiteURL= sURL; +1y#=iM{
sFilePath = sPath; v7R&9kU{
sFileName = sName; F,bl>;{[{
this.nSplitter = nSpiltter; %|I|Mc
Mc6y'w
96BMJE'
} G1l(
GB=q}@&8p
e'`oisJU?q
public String getSSiteURL() N4:'X6u;
{ gM*s/,;O"
return sSiteURL; x0d+cSw
} TQou.'+v
:U9R 1^}A
yV8).4
public void setSSiteURL(String value) _pS%tPw
{ t'J fiGM
sSiteURL = value; bm4W,
} gU?)
0D'Wr(U(
>W;i2%T
public String getSFilePath() H@zk8]_P
{ b>i=",i\
return sFilePath; w#e'K-=
} AUC< m.
>$y >
d}ZHY[
public void setSFilePath(String value) {ZcZ\Q;6
{ -db+Y:xUZ
sFilePath = value; z)%1i
} C gx?K]>y
- -G1H
fo.m&mKgo
public String getSFileName() E(@;p%:
{ :3B\,inJ
return sFileName; $c}0L0
} my1kF%?
a%dx\&K
_#C}hwOR>X
public void setSFileName(String value) Xo`1#6xsE
{ IfcFlXmt2
sFileName = value; ,<1*
} ! Cl/=0$[L
+2SX4Kxu
h uJqqC
public int getNSplitter() #lF<="y%X
{ f[IchCwX
return nSplitter; i.sq^]j
} guv@t&;t0
ZhsZywM
"b 0cj
public void setNSplitter(int nCount) %U GlAyj
{ >v[(w1?rX
nSplitter = nCount; ^mi4q[PM
} N-gRfra+8L
} !qlGt)G3
blcKtrYg
vgj^-
/* D.(G9H
**Utility.java Rs`a@Fn
*/ &>e DCs
package NetFox; YJ$ewK4E#.
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F-^HN%
public class Utility { yf)`jPM1<
(fa?ftK
2JP?6N
public Utility() KeB4Pae|V
{ 4MJzx9#
)\-";?sYky
(L$~zw5gr
} "ILWIzf.]
@@IA35'tc
//线程睡眠 "!tw ,Gp
public static void sleep(int nSecond) 6[.Mx}h6
{ Hc]1mM
try{ N;'HR)
Thread.sleep(nSecond); <(4#4=ivP
} ,SF.@^o@a
catch(Exception e) 8[)]3K x
{ 6#M0AG
e.printStackTrace (); |QLX..
} aMQjoamz
} A Vm{#^p[(
~lqGnNhh7
//日志 U@MP&sdL
public static void log(String sMsg) |xZcT4
{ <zuE=0P~%
System.err.println(sMsg); R9h>I3F=c
} {~fCqP.2
4q13xX
c1kxKxE
public static void log(int sMsg) W@,p9=425
{ KC:4
System.err.println(sMsg); YX`=M
} 9K':Fn2,
} kLt9;<L
-'[(Uzj
:z.Y$]F@
/* drKjLo[y
**TestMethod.java MJ,ZXJXs
*/ xs!g{~V{
package NetFox; ^}Qj}
4iNbK~5j
s;2/Nc
public class TestMethod { 3;MjO*-
sD8m<
NOr <,
public TestMethod() Z.':&7Y
{ ///xx/weblogic60b2_win.exe ncattp
try{ /%YiZ#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E0eQ9BXh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LkGf|yd_
SiteFileFetch fileFetch = new SiteFileFetch(bean); pp]_/46nN
fileFetch.start(); nS+FX&_
} 4r[pMJiq
catch(Exception e){e.printStackTrace ();} o}MzqKfu
Sf&?3a+f
jD/7/G*
} XDkS ^9
M6]0Y@@>
6W;?8Z_1
public static void main(String[] args) *)bd1B#
{ ?#m<\]S<
new TestMethod(); AL]h|)6QpC
} pSQCT
} zD2.Q%`IM
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