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)); Oe x
} ]h~F%
for(int i=0;i<nEndPos.length-1;i++) ZBR^$?nj
{ BdMd\1eMw
nEndPos = nStartPos[i+1]; H#7=s{u
} 6/#+#T
nEndPos[nEndPos.length-1] = nFileLength; '%4fQ%ID}
} W**[:n+
} 9+MW13?
=dH=3iCG
KB^8Z@(+
//启动子线程 V,=5}qozQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XlD=<$Nk7
for(int i=0;i<nStartPos.length;i++) iZ>P>x\
{ p6NPWaBR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _h4]gZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !?_CIt$p
nStartPos,nEndPos,i); akk*f+TD`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FAL#p$y}
fileSplitterFetch.start(); ZB|s/
} B8eZ}9X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZV:df 6S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]zVQL_%,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .?rs5[th*
nEndPos = " + nFileLength); oQrfrA&=M
// fileSplitterFetch[nPos.length-1].start(); ]]_5_)"4
8G3 Z,8P4(
1) K<x
//等待子线程结束 x${C[gxq9F
//int count = 0; L-)ZjXzk
//是否结束while循环 &OZx!G^Z
boolean breakWhile = false; :-#7j} R&
T59FRX
"=n%L +6%
while(!bStop) nTc#I~\
{ -~aG_Bp!($
write_nPos(); cWyf04-?
Utility.sleep(500); WMnSkO
breakWhile = true; W!T[ ^+
s-5#P,Lw
r>! @Z2%s
for(int i=0;i<nStartPos.length;i++) 9(qoME}>=
{ p>kny?AJ
if(!fileSplitterFetch.bDownOver) q+4dHS)x
{ 5x|$q kI
breakWhile = false; p#Po?
break; Q=d:Yz":S
} /s%-c!o^
} )X," NJG
if(breakWhile) -W.-m2:1
break; V~#5^PF{
I$S*elveG
Du +_dr^4
//count++; "=+i~N#Sc
//if(count>4) WF*j^ %5
// siteStop(); ?$ov9U_
} ~:k r;n2
)7!,_r
%QrOEs
System.err.println("文件下载结束！"); <$hv{a
} 4YI6&
catch(Exception e){e.printStackTrace ();} c%O97J.5b
} Ek_&E7
)MSCyPp5
k&:q|[N
//获得文件长度 @aN~97 H\
public long getFileSize() k"%JyO8Y
{ %).I&)i
int nFileLength = -1; AX&Emz-
try{ #g@4c3um|
URL url = new URL(siteInfoBean.getSSiteURL()); >TM{2b,(p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [O'aka Q
httpConnection.setRequestProperty("User-Agent","NetFox"); `KLr!<i()
fj['M6+wd
R\X;`ptT
int responseCode=httpConnection.getResponseCode(); \2[tM/+Bs
if(responseCode>=400) %-fS:~$
{ p %.Adxx
processErrorCode(responseCode); g$mMH
return -2; //-2 represent access is error bC"h7$3
} Ac{TqiIv
^b~ZOg[p
_t;^\"\
String sHeader; -IVWkA)7
OGLA1}k4
_1O .{O
for(int i=1;;i++) qhG2j;
{ mJd8?d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4;)t\9cy_
//Utility.log(in.readLine()); %"oGJp
sHeader=httpConnection.getHeaderFieldKey(i); G;#xcld
if(sHeader!=null) YahW%mv`d
{ T`j{2
if(sHeader.equals("Content-Length")) 55TFBDc
{ kI04<!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Het>G{
break; %Jd!x{a`>A
} Avyer/{
} ~ArRD-_t
else a%a0/!U[
break; >dgq2ok!u
} ar 7.O;e
} _qk&W_u
catch(IOException e){e.printStackTrace ();} \(=xc2
catch(Exception e){e.printStackTrace ();} v9,cL.0&
|;(P+Q4lB
IO7gq+
Utility.log(nFileLength); A /c
/E{tNd^S
-Jv3D$f]a
return nFileLength; "".a(ZGg
} :/6aBM?
v8'XchJ
.}eM"Kv
//保存下载信息（文件指针位置） .waj.9&[l
private void write_nPos() R}3th/qf
{ K0o${%'@7
try{ wpC.!T
output = new DataOutputStream(new FileOutputStream(tmpFile)); ki2`gLK
output.writeInt(nStartPos.length); =zrfh-lwH
for(int i=0;i<nStartPos.length;i++) @c"s6h&
{ eHGx00:
// output.writeLong(nPos); :5&UWL|
output.writeLong(fileSplitterFetch.nStartPos); M&q~e@P
output.writeLong(fileSplitterFetch.nEndPos); DnhbMxh8o
} 90Sras>F
output.close(); k#~oagW_Gw
} AY"wEyNU
catch(IOException e){e.printStackTrace ();} sUR5Q/Q
catch(Exception e){e.printStackTrace ();} FqGMHM\J
} )MTf
yP} |8x
nQ|($V1?W
//读取保存的下载信息（文件指针位置） Y`$\o
private void read_nPos() 50A\Y)i_mZ
{ xe(7q1
try{ g2^{+,/^K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iqB%sIP
int nCount = input.readInt(); 2!CL8hG5:
nStartPos = new long[nCount]; $_eJ@L#
nEndPos = new long[nCount]; S=`$w
for(int i=0;i<nStartPos.length;i++) GcA|JS=>
{ wL]#]DiE
nStartPos = input.readLong(); `HYj:4v'
nEndPos = input.readLong(); 2?:OsA}
} (d,OLng
input.close(); MT)q?NcG
} ^r(]S%
catch(IOException e){e.printStackTrace ();} 8KkN "4'
catch(Exception e){e.printStackTrace ();} PA*k|
} ?UIW&*h}
Z5P4 H
l=Jw6F+5
private void processErrorCode(int nErrorCode) pV\>?
{ Z-_Xt^N
System.err.println("Error Code : " + nErrorCode); 7B5b +
} PBEi"`i
-bSM]86
Pf?&ys6
//停止文件下载 CK|AXz+EN
public void siteStop() ^5?|Dj
{ car|&b
bStop = true; p/7'r
for(int i=0;i<nStartPos.length;i++) ]mNsG0r6
fileSplitterFetch.splitterStop(); Sd.Km a
(~5]1S}F
Slv:CM M
} `)KGajB
} MF*4E9Ue.
//负责部分文件的抓取 L\bcR
**FileSplitterFetch.java (n2_HePE
*/ 3,*A VcQA
package NetFox; vd$>nJ"
h#)\K| qs
B`3z(a92S
import java.io.*; |f1^&97=+
import java.net.*; 2>9..c
s?k:X ~m
SfrM|o
public class FileSplitterFetch extends Thread { h -091N
8I#^qr5
Y,,Z47% E
String sURL; //File URL hcYqiM@8>
long nStartPos; //File Snippet Start Position d1t_o2
long nEndPos; //File Snippet End Position +7 j/.R
int nThreadID; //Thread's ID 4f~q$Sf]<
boolean bDownOver = false; //Downing is over lg ,%
boolean bStop = false; //Stop identical Y$)y:.2#
FileAccessI fileAccessI = null; //File Access interface <HS{A$]
MYz!zI
eAjR(\f>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZZ :*c"b:
{ 0jxXUWO
this.sURL = sURL; 55] MRv
this.nStartPos = nStart; k 7@:e$7
this.nEndPos = nEnd; ~q/~ u
nThreadID = id; i|/G!ht^e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /|h+,]< >
} YD9vWk\/
0Ny +NE:6M
)#hR}|
public void run() @;{ZnRv14
{ x{So
while(nStartPos < nEndPos && !bStop) 7 TM-uA$
{ k$#1T +(G
[ z/G
#u\~AO?h
try{ z-"P raP
URL url = new URL(sURL); S+mBVk"-~S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I1dOMu9
httpConnection.setRequestProperty("User-Agent","NetFox"); d>#X+;-k
String sProperty = "bytes="+nStartPos+"-"; g1y@z8Z{
httpConnection.setRequestProperty("RANGE",sProperty); O ]-8 %
Utility.log(sProperty); yiH;fK+x
4"iI3y~Gw
K)Z~ iBRM
InputStream input = httpConnection.getInputStream(); At[SkG}b
//logResponseHead(httpConnection); 9oP
"qZTgCOY2
FLkZZ\
byte[] b = new byte[1024]; I.~=\%Z{
int nRead; ,qV7$u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) loBW#>
{ )u]=^
nStartPos += fileAccessI.write(b,0,nRead); ]+w 27!
//if(nThreadID == 1) _ogN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %X%f0J
} )7P>Hj
i/!KUbt
WHLTJ]OB
Utility.log("Thread " + nThreadID + " is over!"); b{x/V9&|
bDownOver = true; )/OIzbA3#
//nPos = fileAccessI.write (b,0,nRead); [{&OcEf
} *] >R
catch(Exception e){e.printStackTrace ();} f/0k,~,*
} B(eiRr3
} YbZ?["S&
d]sg9`
YT)1_>*\
//打印回应的头信息 Su +<mW
public void logResponseHead(HttpURLConnection con) NQiu>Sg
{ zNn
for(int i=1;;i++) ,LLx&jS
{ &Akw V-
String header=con.getHeaderFieldKey(i); jSdC1,wR
if(header!=null) @q@I(%_`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qzZ;{>_f
Utility.log(header+" : "+con.getHeaderField(header)); oGbh*
else "dYT>w
break; BPOT!-
} <@4V G
} vYo~36
~Xr[d07bC
Zba<|C
public void splitterStop() LCHw.
{ K>\v<!%a
bStop = true; 889^P`Q5
} 8LuU2Lo
2<AQ{ c
{aopGu?i
} W55kR.X6M
&a\G,Ma
:Z83*SPc
/* z$/s` |]
**FileAccess.java kaECjZ_&+
*//文件访问(定位，写) o##!S6:A
package NetFox; E=,fdyj.
import java.io.*; Gu2=+?i?h
2J3y 1
U:PtRSdn!b
public class FileAccessI implements Serializable{ G%}k_vi&q
.+lx}#-#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tTt}=hQpgX
RandomAccessFile oSavedFile; aHitPPlq
long nPos; O[|X=ZwR:l
HA&hu/mw_
,,S 2>X*L
public FileAccessI() throws IOException :#N]s
{ RH$YM `cZ
this("",0); .8[uEQ_L
} I-Hg6WtB
;1r|Bx<5
}`76yH^c
public FileAccessI(String sName,long nPos) throws IOException \t=#MzjR
{ .^ba*qb`{
oSavedFile = new RandomAccessFile(sName,"rw"); 85A7YraL
this.nPos = nPos; 5+(Cp3
oSavedFile.seek(nPos); Tj6Czq=*%T
} ZF<$6"4N
tq*6]q8c>
}Cb-7/
public synchronized int write(byte[] b,int nStart,int nLen) @FRas00)|
{ I(/*pa?m{
int n = -1; ? Z2`f6;W4
try{ j5~~%
oSavedFile.write(b,nStart,nLen); 8\?H`NN
n = nLen; Z:,`hW*A6
} }+)q/]%
catch(IOException e) h=kC3ot\
{ 4`+R |"4
e.printStackTrace (); =&: |a$C
} g6?5
N{a=CaYi+
:{KpnJvd
return n; og4mLoLA
} F$YT4414
#3FsK
O6\c1ha
} A":cS }Ui
JEeXoGKd
))7CqN
/* bq}`jP~#
**SiteInfoBean.java #aE>-81SS&
*/ mWMtz]M}
package NetFox; 1>bNw-kz7
*3fhVl=8^*
CX]L'
public class SiteInfoBean { gL7rX aj
7oCY@>(f
z)u\(W*\iA
private String sSiteURL; //Site's URL 8rLhOA
private String sFilePath; //Saved File's Path 6R#igLm
private String sFileName; //Saved File's Name [z'jL'\4
private int nSplitter; //Count of Splited Downloading File AU8sU?=
8/"C0I (G
qtz~Y~h|>
public SiteInfoBean() q0nIJ(
{//nSplitter的缺省值为5 }Am5b@g"$Y
//default value of nSplitter is 5 R)=){SI:1)
this("","","",5); M>{*PHze0
} K d{o/R
;O<-4$
|[)pQGw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sy(.p^Z
{ IJ7wUZp"
sSiteURL= sURL; CFu^i|7o
sFilePath = sPath; sH%Ts@Pl
sFileName = sName; wZ_"@j<
this.nSplitter = nSpiltter; onIZ&wrk
8\+DSA
`~NjBtQ
} Q&w"!N
l.BiE<&
Ieh<|O,-C
public String getSSiteURL() UsdMCJ&G
{ 5eM{>qr}
return sSiteURL; nL]eGC
} 6$H`wDh#(&
_Ec"[xW
{"|la;*I
public void setSSiteURL(String value) D&OskM60
{ ({cWb:+r
sSiteURL = value; D"IxQ2}k
} )OK"H^}f
3XDuo|(
1aPFpo!
public String getSFilePath() '#jZ`
{ !Yz CK*av1
return sFilePath; Rt@O@oDI
} ` ^;J<l
#9{2aRCJ
b&RsxW7
public void setSFilePath(String value) 9!ARr@ ;
{ O.{
sFilePath = value; 6lUC$B Y
} 7/)0{B4U'
$h5QLN
J.]`l\
public String getSFileName() %Nx,ZD@
{ 7t/Y5Qf
return sFileName; X(Z(cY(
} @S6@pMo,
Z1]4:
#];ulDq
public void setSFileName(String value) Af}o/g
{ |<uBJ-5
sFileName = value; g@Rs.Zq
} 7JBr{3;eS
{e0(M*u
z|zEsDh;
public int getNSplitter() Q(4~r+
{ %\~U>3Q
return nSplitter; . "7-f]!
} G9@5 !-
^~dC&!D
3Z7gPU!H=
public void setNSplitter(int nCount) >4os%T
{ ,V{Bpr
nSplitter = nCount; '-3K`[
} "6v_<t`q"
} n$E$@
w}e_17A
E%a&6W
/* Z/ L%?zH
**Utility.java K#VGG,h7Y
*/ MeAY\V%G=o
package NetFox; \C{Zqo,
/)<kG(Z
.kJu17!
public class Utility { >;%LW} %
b1%w+*d<z
Y' 5X4Ks|
public Utility() RMdU1@
{ j]aIJbi
G3h"Eo?>g
p(9[*0.};
} XV,ce~ro[
IYa(B+nB)
//线程睡眠 e*d lGK3l
public static void sleep(int nSecond) A+FQmLS
{ X1BqN+=@9
try{ Dn#UcMO>W
Thread.sleep(nSecond); O9N+<sU=X
} nGur2}>n
catch(Exception e) AoK;6je`K^
{ P,rLyx
e.printStackTrace (); dux_v"Xl
} Mhc5<~?
} MM( ,D& Z
G&4D0f
//日志 -OnKvpeI
public static void log(String sMsg) wNUcL*n
{ d@zxgn7o
System.err.println(sMsg); Yu9VtC1
} XinKG<3!
Pon0(:#1
KIKIag#
public static void log(int sMsg) ^==Tv+T9U
{ JOs kf(
System.err.println(sMsg); {wO.nOB
} <vu~EY0.
} `,4YPjk^
2EO9IxIf
ce719n$
/* l_,6<wWp
**TestMethod.java Mgu9m8 `J
*/ ;ZkY[5
package NetFox; [jEA|rd~}
qLw^Qxo
&3)6WD?:U
public class TestMethod { p0}Yo8?OW
o,xy'
ZVit]3hd
public TestMethod() ~{N#JOY}Z
{ ///xx/weblogic60b2_win.exe z]=Ks_7
try{ NdRE,HWd?$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q6x}\$mL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :`0,f?cE
SiteFileFetch fileFetch = new SiteFileFetch(bean); P]L%$!g
fileFetch.start(); $#wi2Ve=6b
} O"_QDl<ya
catch(Exception e){e.printStackTrace ();} Lmw)Ts>
-w'g0/fD
::3[H$
} 4`7~~:W!M5
#G\-ftA&
Ki%)LQAg
public static void main(String[] args) D%=&euB
{ ~bis!(}p-
new TestMethod(); >4HB~9dKU
} cBHUa}:
} K)h<#F
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