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)); \otWd
} N;\'N ne
for(int i=0;i<nEndPos.length-1;i++) AvfNwE
{ y&V@^"`
nEndPos = nStartPos[i+1]; 9I4K}R
} rk #sy$
nEndPos[nEndPos.length-1] = nFileLength; ax(c#
} V#iPj'*
} V,%=AR5
S:OO0<W
xL\0B,]
//启动子线程 thI F&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Evedc*z~P
for(int i=0;i<nStartPos.length;i++) 97}OL`y
{ ZjF 4v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oz,e/v8~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C#Na&m
nStartPos,nEndPos,i); ; #&yn=^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XT4{Pe7{[P
fileSplitterFetch.start(); (L/_^!ZX
} O6LS(5j2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "hsb8-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <i&_ooX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~vyf4TF<#
nEndPos = " + nFileLength); [5SD_dN
// fileSplitterFetch[nPos.length-1].start(); >Z'NXha
/ G7vwC
B!?%O
//等待子线程结束 d>mo~
//int count = 0; *-8&[D0
//是否结束while循环 Sy0$z39
boolean breakWhile = false; 9po3m]|zy
d'NIV9P`j]
UWd=!h^dt
while(!bStop) ui/a|Q
{ LGw$v[wb
write_nPos(); $7^o#2 B
Utility.sleep(500); pe1R(|H
breakWhile = true; :gWu9Y|{
1pgU}sRk
(&F ,AY3A
for(int i=0;i<nStartPos.length;i++) ZZzMO6US0
{ pC@{DW;V6R
if(!fileSplitterFetch.bDownOver) {#@W)4)cA
{ "i[@P)
breakWhile = false; \D*KGd]M0
break; Na]:_K5Dp
} k@k&}N0{
} v0H@Eg_
if(breakWhile) SC)g^E#
break; 6[ j.@[t
paCV!tP
%z,mB$LY
//count++; 9 a!$z!.
//if(count>4) x"~8*V'0
// siteStop(); .uMn0PE
} o<pf#tifv
+|n*b
z`f($t[
System.err.println("文件下载结束！"); l)1r+@)\
} /rnu<Q#iH
catch(Exception e){e.printStackTrace ();} E/|To
} l3ko?k
N_W}*2(
8c9*\S
//获得文件长度 q_MG?re
public long getFileSize() __G?0*3G
{ \o*5
int nFileLength = -1; )<h*eS{
try{ R6;=n"Ueb
URL url = new URL(siteInfoBean.getSSiteURL()); P2#XKG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K8GP@yD]M
httpConnection.setRequestProperty("User-Agent","NetFox"); P-yjN
<7/R,\Wg~
5m&9"T.w
int responseCode=httpConnection.getResponseCode(); `ZyI!"
if(responseCode>=400) 4;yKOQD|
{ keL&b/@
processErrorCode(responseCode); l5!|I:/*;
return -2; //-2 represent access is error eD?tLj
} Q ayPo]O
jaII r06
OEA&~4&{7
String sHeader; 'vbsvT
n|9-KTe7|*
MyJ%`@+1
for(int i=1;;i++) {?}E^5Z*g
{ =Y|VgV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r1 !@hT
//Utility.log(in.readLine()); `{3<{wgw
sHeader=httpConnection.getHeaderFieldKey(i); L*xhGoC=
if(sHeader!=null) ?PeJlpYzV
{ zPn+V7F
if(sHeader.equals("Content-Length")) "O3tq=Q
{ ls\WXCH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {Aw#?#GPW
break; iT3BF"ZqBO
} fI?>+I5
} C~,a!qY
else EE&K0<?T|:
break; 1"MhGNynB>
} riY~%9iV'
} %*A0#F
catch(IOException e){e.printStackTrace ();} .sha&
catch(Exception e){e.printStackTrace ();} Y!-M_v/
46_xyz3+
`2("gUCm
Utility.log(nFileLength); PUT=C1,OFR
!/'t5~x[
<J<{l
return nFileLength; _S<3\%(0
} #+Ir>GU
#L=x%8B
+%yfcyZ.
//保存下载信息（文件指针位置） x kx^%3dV
private void write_nPos() ey7 f9
{ !;q&NHco
try{ _{I3i:f9X8
output = new DataOutputStream(new FileOutputStream(tmpFile)); q9KHmhUD
output.writeInt(nStartPos.length); I&#| w"/"U
for(int i=0;i<nStartPos.length;i++) x nsLf?>]
{ eI$oLl@
// output.writeLong(nPos); _mqL8ho
output.writeLong(fileSplitterFetch.nStartPos); )B"jF>9)[
output.writeLong(fileSplitterFetch.nEndPos); ]sf7{lVT
} cLpYW7vZ[
output.close(); ~7*.6YnI
} |mxDjgq
catch(IOException e){e.printStackTrace ();} !JHL\M>A5
catch(Exception e){e.printStackTrace ();} XKj|f`
} ]#)()6)2v
BTqS'NuT
k+# %DK
//读取保存的下载信息（文件指针位置） _C%3h5
private void read_nPos() JFcLv=U
{ >*~L28Fyn
try{ `uv2H$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .F98G/s
int nCount = input.readInt(); TV)h`\|Z*
nStartPos = new long[nCount]; M'7fO3&|
nEndPos = new long[nCount]; M8MRoA6F
for(int i=0;i<nStartPos.length;i++) u@W|gLT1
{ hO\<%0F
nStartPos = input.readLong(); .F4>p=r
nEndPos = input.readLong(); GFj{K
} =)0,#9k U]
input.close(); OcR$zlgs[v
} %<\vGqsM
catch(IOException e){e.printStackTrace ();} mitHT :%r2
catch(Exception e){e.printStackTrace ();} 8g@<d^8@
} <GS^
q(
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private void processErrorCode(int nErrorCode) bkOv2tZ
{ Q3kdlxXR
System.err.println("Error Code : " + nErrorCode); -]0OKE&
} =Gpylj7?~
~8'sBT
-^&<Z 0m
//停止文件下载 [<Mx2<8f
public void siteStop() 2%DSUv:H%
{ ($q-_m
bStop = true; "Gsc;X'id
for(int i=0;i<nStartPos.length;i++) *>Ns_su7W
fileSplitterFetch.splitterStop(); TH%Qhv\]
;v}GJ<3
j$M h+5
} q}i]'7
} F|SXn\
//负责部分文件的抓取 U$O\f18
**FileSplitterFetch.java m ifxiV
*/ wT6"U$cV
package NetFox; pj\u9 L_
du<tGsy
R5N%e%[
import java.io.*; CuaVb1r
import java.net.*; =6j&4p `
R{C(K(5/
x>**;#7)
public class FileSplitterFetch extends Thread { SL Ws*aq
ak7bJ~)X=
qk%;on&`
String sURL; //File URL ih58<Up5
long nStartPos; //File Snippet Start Position {c6=<Kv
long nEndPos; //File Snippet End Position `!obGMTQ<
int nThreadID; //Thread's ID }s7$7
boolean bDownOver = false; //Downing is over hr#M-K
boolean bStop = false; //Stop identical {BP{C=p
FileAccessI fileAccessI = null; //File Access interface Tm~" IB*
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &C`Gg<
{ a!zz6/q[
this.sURL = sURL; D#_3^Kiawj
this.nStartPos = nStart; :NhO2L
this.nEndPos = nEnd; 4X!/hI=jq
nThreadID = id; 2Z+Wu3#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xs{3pkTYD
} ]N~2 .h
=mO vs
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public void run() .T}Wdng
{ QVv#fy1"6
while(nStartPos < nEndPos && !bStop) Q1U\D
{ h=W:^@G
1vS#K=sb
Ow+GS{-q
try{ ] ]u s %
URL url = new URL(sURL); 1auIR/=-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KI.q@zO6|
httpConnection.setRequestProperty("User-Agent","NetFox"); 6/f7<
String sProperty = "bytes="+nStartPos+"-"; k9<;woOBO
httpConnection.setRequestProperty("RANGE",sProperty); qLO4#CKCL6
Utility.log(sProperty); +jAGGv^)
fW{(lPx
oI?3<M^
InputStream input = httpConnection.getInputStream(); S(k3 `;K
//logResponseHead(httpConnection); .yMEIUm
OC_+("N
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byte[] b = new byte[1024]; piJu+tUy
int nRead; ~Q Oe##
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F|IAiE
{ @D]5civm_
nStartPos += fileAccessI.write(b,0,nRead); ;0Q4<F
//if(nThreadID == 1) 1jx:;j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q$a{\*[:+
} +! ]zA4x
DEBB()6,
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Utility.log("Thread " + nThreadID + " is over!"); evya7^,F
bDownOver = true; 9)h"-H;5:
//nPos = fileAccessI.write (b,0,nRead); )cX*I gO
} 9>=;FY
catch(Exception e){e.printStackTrace ();} 9"N~yKa`"K
} B~'vCuE
} >f|||H}Snw
P9/q|>F
`}D,5^9]
//打印回应的头信息 kI,yU}<Fq
public void logResponseHead(HttpURLConnection con) g!FuY/%+
{ [T|aw1SoN
for(int i=1;;i++) S){)Z
{ rF3wx.
String header=con.getHeaderFieldKey(i); !eGC6o}f
if(header!=null) Bj+S"yS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #QS`_TlKk
Utility.log(header+" : "+con.getHeaderField(header)); Q1T$k$n
else IDad9 Bx
break; ]vz%iv_
} fJ=0HNmX
} sSr&:BOsi
$|zX|
d8DV[{^
public void splitterStop() `vU%*g&R
{ V)3KS-
bStop = true; ^\hG"5#
} 272q1~&
F6LH $C
-zCH**y%1
} w0[6t#$F
=h-U
t0(A4E
/* ZAW^/bo<
**FileAccess.java 9#23FK
*//文件访问(定位，写) Yc`o5Q\>
package NetFox; dhC$W!N7!
import java.io.*; 0XOp3
+UCG0D
'<gI8W</
public class FileAccessI implements Serializable{ raW>xOivR
g!|=%(G=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k 9_`(nx
RandomAccessFile oSavedFile; $CRm3#+ ~
long nPos; kPKB|kP\
! :Y:pu0
*Hg>[@dP0
public FileAccessI() throws IOException 7dN*lks
{ S:u:z=:r
this("",0); 'I`&Yo~c9
} `oAW7q)~
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bpOYHc6,*`
public FileAccessI(String sName,long nPos) throws IOException 'g">LQ~a+
{ ):P?
oSavedFile = new RandomAccessFile(sName,"rw"); # ncRb
this.nPos = nPos; _H9 MwJ
oSavedFile.seek(nPos); d|jNf</`
} #"}JdBn
.nO\kgoK
&U{#Kt5q
public synchronized int write(byte[] b,int nStart,int nLen) C/_ZUF(V
{ Tg7an&#
int n = -1; fPU`/6
try{ k}S :RK
oSavedFile.write(b,nStart,nLen); goLL;AL
n = nLen; 3_C|z,\:
} pXtl 6K%
catch(IOException e) ^Xz@`_I
{ ?#Ge.D~u
e.printStackTrace (); x" 7H5<
} |a8iZ9/D6
B=U 3
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return n; dR K?~1
} bes<qy
4M^=nae
# '=a=8-$
} jY&k
uY0lR:|
T!uM+6|Y
/* QER?i;-wb
**SiteInfoBean.java H h4WMZJG
*/ at@G/?
package NetFox; NxfOF
C:GK,?!Jn'
9U7nKJ+iby
public class SiteInfoBean { wDw[RW3
N[?N5~jG
OwuE~K7b{
private String sSiteURL; //Site's URL aasoW\UG
private String sFilePath; //Saved File's Path 5b5x!do
private String sFileName; //Saved File's Name |Yx~;q:
private int nSplitter; //Count of Splited Downloading File -Mip,EO
P=qa::A
>3ZFzh&OYQ
public SiteInfoBean() CZ8KEBl
{//nSplitter的缺省值为5 rDl*d`He!
//default value of nSplitter is 5 qjwxhabc
this("","","",5); /{Is0+)
} ag;Q F
/Jta^Bj
Y&`=jDI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W'els)WJ|x
{ hC:n5]K
sSiteURL= sURL; JR'
sFilePath = sPath; q~ tz? T_
sFileName = sName; Mc@e0
this.nSplitter = nSpiltter; 8."]//V
xP_cQwm`1
a@8v^G
} AW%50V
[<7@{;r
%W'v}p
public String getSSiteURL() ^9m\=5d
{ -N6f1>}pE
return sSiteURL; ; a/X<
} %) /s;Q,
phQUD
EJj.1/]|r
public void setSSiteURL(String value) 5]~'_V
{ c>,KZ!
sSiteURL = value; <5d~P/,
} GC<l#3+
XND|h#i8
PvzcEV
public String getSFilePath() 9Q.rMs>qj
{ S O4u9V
return sFilePath; dW)B1iUo!
} 2$9odD<r
Ac96 [
ZLc -RM
public void setSFilePath(String value) %}[i'rT>
{ AmvEf
sFilePath = value; }\hVy(\c
} x`U^OLV
d+<G1w&z
%fc!2E9|
public String getSFileName() ng[Ar`
{ 8G9s<N}5&u
return sFileName; [I0:=yJ+
} j1^I+j)
63^O|y\W8
>l]Xz*HE
public void setSFileName(String value) \jh'9\
{ &@G:G(
sFileName = value; P !AEf#1
} !-ok"k0,u
f6EZ( v
\"qY"V
public int getNSplitter() Vl5`U'^qx
{ b v G/|U
return nSplitter; T m,b,hi$
} 2-&k^Gl!:
nx@=>E+a
g~ZvA(`
public void setNSplitter(int nCount) =w;F<M|Y
{ :Uz|3gq
nSplitter = nCount; \O}E7-
} g=39C>
} X]'{(?Ch
2I%MAb&1@
%;cddLQ\xY
/* %.vQU @2A
**Utility.java VAWF3
*/ dOa+(fMe
package NetFox; RtGWG*v4]
u0 P|0\
~F7-HaQJ
public class Utility { s&A} h
2K< 8
}d&_q7L@@6
public Utility() VE#Wb7
{ c(J!~7
1cxrH+N
lAi6sPG)0
} j:<n+:HC
*Y,x|F
//线程睡眠 U(a#@K!H
public static void sleep(int nSecond) .+qQYDEw
{ Fa?~0H/DL
try{ RwKdxK+;
Thread.sleep(nSecond); Mc=$/ o
} OJ,`
catch(Exception e) uPhK3nCGo
{ t,,k
e.printStackTrace (); 6tXq:
} Ci?Ss+|
} Z LB4m`
3cFf#a#
//日志 AZ0;3<FfLp
public static void log(String sMsg) H+1-]'g`
{ ,X#2\r<|
System.err.println(sMsg); 9G9fDG#F\I
} "k/;[ Wt]
j!_;1++q
H#NCi~M>3
public static void log(int sMsg) %4ePc-
{ gMY1ts}Z
System.err.println(sMsg); 2#P*,
} 3wOZ4<B
} M*!agh
lU@]@_<
rv&<{@AS~
/* \wo?47+=
**TestMethod.java d_CKP"TA
*/ 0>C T=(A
package NetFox; n.T&}ZPz\v
,#Iu 7di
EwuO&q
public class TestMethod { >XK PTC5H
@*OZx9
@<&5J7fb
public TestMethod() j2ve^F:Q
{ ///xx/weblogic60b2_win.exe ~T9/#-e>BF
try{ QFw +cy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z8zmHc"IH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]or>?{4g
SiteFileFetch fileFetch = new SiteFileFetch(bean); [p{#XwN
fileFetch.start(); s8wmCzB~
} 61.Brp.eP
catch(Exception e){e.printStackTrace ();} J!0DR4=Xi
!6BW@GeF]
:ZTc7}
} :axRoRg
xGu r
PfreAEv,
public static void main(String[] args) 5i>$]*o
{ b@rVo;
new TestMethod(); }'""(,2
} ,-izEr
} D&/kCi=R
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