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)); 256V xn
} QTjnXg?Ri
for(int i=0;i<nEndPos.length-1;i++) U]O>DM^'
{ eY3<LVAX
nEndPos = nStartPos[i+1]; X6n8Bi9Ik
} L#`X;:
nEndPos[nEndPos.length-1] = nFileLength; C@@PLsMg
} D1Q]Z63,
} ]|B_3*A
p}|<EL}Z9
H.)J?3
//启动子线程 G PL^!_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^6PKSEba
for(int i=0;i<nStartPos.length;i++) ->J5|c#
{ *!`bC@E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y+$a}=cb0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ba9"IXKH
nStartPos,nEndPos,i); }C5Fvy6uz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /_tN&[
fileSplitterFetch.start(); <(BIWm*
} ])vqXjN6"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8hZc#b;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,A>cL#Oe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r ['zp=9
nEndPos = " + nFileLength); /F}dC/W
// fileSplitterFetch[nPos.length-1].start(); 'F7UnkKO|
s"X0Jx}
X92I==-w
//等待子线程结束 nC#SnyUO
//int count = 0; {"\pMY'7
//是否结束while循环 X^d}eWP`I
boolean breakWhile = false; \d QRQL{LL
s~g]`/h$r
UDHMNubB
while(!bStop) #kAk d-QY6
{ ?)e6:T(
write_nPos(); 'o1lJ?~kH
Utility.sleep(500); 4YCuO%
breakWhile = true; j/hm)*\io
68nPz".X
X'usd$[.
for(int i=0;i<nStartPos.length;i++) uo7[T*<Q
{ "2`/mtMon
if(!fileSplitterFetch.bDownOver) L+0O=zJF
{ z#+Sf.
breakWhile = false; W ZW:q
break; EP6@5PNZ
} KZ|p_{0&
} ^-s`$lTp
if(breakWhile) ,/UuXX
break; ab*O7v
W(PNw2
u\=yY.
//count++; -9$.&D|
//if(count>4) \|$GBU
// siteStop(); Qe]aI7Ei
} 2z9N/SyN
%wIb@km
gA&`vnNP
System.err.println("文件下载结束！"); sh}eKwh
} cd)}a_9
catch(Exception e){e.printStackTrace ();} 3q`Uq`t4mR
} 57:27d0y
T$tO[QR/
4JGU`L:~
//获得文件长度 /(Ryh6M
public long getFileSize() FyRr/0C>
{ J%8hf%!ud
int nFileLength = -1; S|T*-?|
try{ I3dUI~}u
URL url = new URL(siteInfoBean.getSSiteURL()); je=XZ's,i~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); me@EKspX
httpConnection.setRequestProperty("User-Agent","NetFox"); ]wV_xZ)l^A
]?~[!&h
"qw.{{:tf
int responseCode=httpConnection.getResponseCode(); [ejl #'*5
if(responseCode>=400) BV]$= e'
{ wQ\bGBks
processErrorCode(responseCode); &u~%5;
return -2; //-2 represent access is error -_BjzA|
} .$ 5*v
<Sp>uhet1
:bz;_DZP
String sHeader; BzI(
Klqte*!
%(g!,!l)
for(int i=1;;i++) zCSLV>.F
{ @;>Xy!G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5>~q4t)6z}
//Utility.log(in.readLine()); >;k~B
sHeader=httpConnection.getHeaderFieldKey(i); q #X[oVq
if(sHeader!=null) |}<!O@<|
{ n)R[T.E)+
if(sHeader.equals("Content-Length")) HkyN$1s
{ ;f2<vp;U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CV*
break; 2yndna-
} %QX"oRMn0
} ?^{Ey[)'(
else | @p
break; >`+lEob
} qEnmms1
} NucLf6
catch(IOException e){e.printStackTrace ();} . "`f~s\G
catch(Exception e){e.printStackTrace ();} OZE.T-{
}62Q{>`
$"`e^J9!!
Utility.log(nFileLength); c.h_&~0qf
<"!'>ZUt
P;p;o]
return nFileLength; B{lL}"++0
} (t"rzH
wy?Hp*E
@gihIysf
//保存下载信息（文件指针位置） qim|=
private void write_nPos() 5S&^mj-9
{ uN(N2m
try{ a>Xq
output = new DataOutputStream(new FileOutputStream(tmpFile)); *|)O
output.writeInt(nStartPos.length); ^tl&FWF
for(int i=0;i<nStartPos.length;i++) 1:Xg&4s
{ !4mAZF b
// output.writeLong(nPos); bE2{^5iG
output.writeLong(fileSplitterFetch.nStartPos); A9M/n^61
output.writeLong(fileSplitterFetch.nEndPos); RJLhR_t7n
} jN2Xoh9
output.close(); (eO_]<wmky
} q4ej7T8
catch(IOException e){e.printStackTrace ();} @{x+ln1r
catch(Exception e){e.printStackTrace ();} e[t1V/ah
} EtA,ow
<`*v/D7\02
U<U?&hB\@
//读取保存的下载信息（文件指针位置） M,bcTa8
private void read_nPos() ^%Fn|U\u
{ 7dXh,sD
try{ zM<yd#`yt8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n_-k <3
int nCount = input.readInt(); Y~I6ee,\
nStartPos = new long[nCount]; =8x-+u5}rK
nEndPos = new long[nCount]; 3vF-SgCV
for(int i=0;i<nStartPos.length;i++) " {Nw K
{ S{qn^\0
nStartPos = input.readLong(); "gq_^&
nEndPos = input.readLong(); *uMtl'
} rcG-Vf@
input.close(); 2%t!3F:
} 9XW[NY#)#
catch(IOException e){e.printStackTrace ();} fFd"21>
catch(Exception e){e.printStackTrace ();} a|@1RH>7H
} LrnE6U9
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\t]aBT,
private void processErrorCode(int nErrorCode) "'mr0G9X
{ _tVrLb7`s
System.err.println("Error Code : " + nErrorCode); f`_6X~ p
} ]\oE}7K%r
f{f|frs
'2c4 4F)i
//停止文件下载 \DRYqLT`
public void siteStop() F` ]s
{ Xc7Qu?}
bStop = true; p|R]/C0f
for(int i=0;i<nStartPos.length;i++) Rj{D#5
fileSplitterFetch.splitterStop(); QD*(wj
-vBk,;^>
({p@Ay
} Op:7EdT#
} ($:JI3e[;
//负责部分文件的抓取 =/F\_/Xw
**FileSplitterFetch.java S[oRq
*/ xm}`6B^f
package NetFox; QzA/HP a
qAR}D~t
J`{HMv
import java.io.*; )z2hyGX
import java.net.*; [bJAh ` I
{t&+abY
p&,2@(Q
public class FileSplitterFetch extends Thread { 3W}xYYs]^
#ui7YUR=2
]e]l08
String sURL; //File URL fIcra
long nStartPos; //File Snippet Start Position >,%7bq=T!
long nEndPos; //File Snippet End Position NuKx{y}P
int nThreadID; //Thread's ID OX/}j_8E^(
boolean bDownOver = false; //Downing is over OPwO`pN
boolean bStop = false; //Stop identical Oz_|pu
FileAccessI fileAccessI = null; //File Access interface 3ZU<u;
&y=~:1&f
pM'AhzS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oFUP`p%[
{ a]|k w4
this.sURL = sURL; <IL$8a
this.nStartPos = nStart; )9JuQ_R
this.nEndPos = nEnd; +{S^A)
nThreadID = id; ceP1mO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *ocbV`
} >VWH bo
nH]F$'rtA
)x*pkE**c
public void run() Gm1vVHAxv
{ )0NE_AZ?
while(nStartPos < nEndPos && !bStop) w/m~#`a
{ SgocHpyg
obhq2sK
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try{ h*-j
URL url = new URL(sURL); =1Mh%/y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $I-i=:}g
httpConnection.setRequestProperty("User-Agent","NetFox"); zSFqy'b.M-
String sProperty = "bytes="+nStartPos+"-"; xlWTHn!j
httpConnection.setRequestProperty("RANGE",sProperty); xkzC+ _A
Utility.log(sProperty); O;*.dR
p%6j2;D
t'0dyQ%u
InputStream input = httpConnection.getInputStream(); `[5QouPV
//logResponseHead(httpConnection); sj?7}(s
&Kgl\;}
Qv@Z#
byte[] b = new byte[1024]; |%~sU,Y\(
int nRead; .5x+FHu7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g+98G8R
{ *"D8E^9
nStartPos += fileAccessI.write(b,0,nRead); enGjom
//if(nThreadID == 1) -dn\*n5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h .Iscr^~
} Q0j$u[x6s
Q+\?gU]
D,rs)
Utility.log("Thread " + nThreadID + " is over!"); &LS&O
bDownOver = true; C%csQ m
//nPos = fileAccessI.write (b,0,nRead); -a[]#v9
} v*7lJNN.
catch(Exception e){e.printStackTrace ();} ?Q)z5i'g#
} eY1$smh t
} HwH Wi
n8eR?'4
uII:Y{G
//打印回应的头信息 0#rv.rJ{
public void logResponseHead(HttpURLConnection con) !be6}
{ iPxhDn<B
for(int i=1;;i++) 3S'juHTe
{ ]jz%])SzH
String header=con.getHeaderFieldKey(i); +0Rr5^8u
if(header!=null) '}{J;moB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #D$vH
Utility.log(header+" : "+con.getHeaderField(header)); YpT x1c-
else YEWHr>&Z
break; 7lvUIc?krW
} av(d0E}}b
} {g2cm'hD
IPU'M*|Q
.-;K$'YG
public void splitterStop() 6}.B2f9
{ Ds$8$1=L=k
bStop = true; \]U@=w
} \*H/YByTb
dF{3~0+,
j[XA"DZR<
} 8z^?PZ/
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!<!sB)
/* kSH3)CC P
**FileAccess.java b'^OW
*//文件访问(定位，写) ${#5$U+kI
package NetFox; ^j?\_r'j
import java.io.*; L!3AiAnr
W>Y8 u8
6u3DxFiTm
public class FileAccessI implements Serializable{ :z%vNKy1
&+-ZXN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S<f&?\wK=v
RandomAccessFile oSavedFile; J_s?e#s
long nPos; =z]&E 78Y
K,[g<7X5
2*Uwp;0
public FileAccessI() throws IOException O`O{n_o^u
{ aC>r5b#:
this("",0); #D3e\(
} Hw5\~!FX
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/>XfK,c-
public FileAccessI(String sName,long nPos) throws IOException Z&=K+P
{ BBw`8!
oSavedFile = new RandomAccessFile(sName,"rw"); L`YnrDZK
this.nPos = nPos; ^Ois]#py
oSavedFile.seek(nPos); ^>uzMR!q5
} +15j^ Az
h:(Jes2
-gh',)R
public synchronized int write(byte[] b,int nStart,int nLen) l!\C"f1o,
{ +~=>72/r
int n = -1; p8BAan3
try{ FyYQ4ov0&o
oSavedFile.write(b,nStart,nLen); )1O *~%
n = nLen; __c:$7B/4U
} |v8>22y
catch(IOException e) 9u1)Kr=e
{ )_b#c+
e.printStackTrace (); yw5MlZ4P=
} 4hztYOhJ{
EuqmA7s8A
~)D2U:"^xm
return n; C81+nR
} ;)[RG\
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E$/`7p8)
} 3=)/-l
z-uJ+SA
zzuDI_,/
/* B4R!V!Z*
**SiteInfoBean.java 'g#Ml`cm
*/ fyx-VXu
package NetFox; <"/Y`/
E8=.TM]L
%p"x|e
public class SiteInfoBean { '/SMqmi
SxC$EQgL
$I-$X?
private String sSiteURL; //Site's URL q^Lj)zmnK
private String sFilePath; //Saved File's Path ^o"9f1s5
private String sFileName; //Saved File's Name P6S^wjk
private int nSplitter; //Count of Splited Downloading File <(?ahO5
y<k-dbr
Gu~y/CE'
public SiteInfoBean() N2;T\xx,
{//nSplitter的缺省值为5 |A7Yv
//default value of nSplitter is 5 :D-d`OyjG>
this("","","",5); }f^r@3Cb3
} jfl7L"2
b^ly
J @"wJEF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d7^:z%Eb|
{ W+a>*#*
sSiteURL= sURL; Pf6rr9
sFilePath = sPath; W$N_GR'4
sFileName = sName; s>~!r.GC
this.nSplitter = nSpiltter; (G}*ho
ag14omM-
G?e,Q$
} 6,uW{l8L
CBs0>M/
}k duN0
public String getSSiteURL() C>N)~Ut
{ 1]fqt[*)
return sSiteURL; DkA cT[
} Q0,]Q ]_
-a]oN:ERb
O\XN/R3
public void setSSiteURL(String value) ,y,NVF
{ i+Px &9o<9
sSiteURL = value; ]0xbvJ8oK
} [xk1}D
@8|- C
9Z6] ];8E
public String getSFilePath() U{h5uezD
{ c%Yvj
return sFilePath; g{8>2OK$c
} <N=p_m 2T
0^]E-Zf
,L\OhT
public void setSFilePath(String value) %D\TLY
{ /Y:_qsO1
sFilePath = value; B y6:
} 9HRYk13ae
J@H9nw+Q
D._q'v<
public String getSFileName() Sq UoXNw
{ '_g8fz 3
return sFileName; W&}R7a@:<~
} MT$OjH'Q`
7}%3Aw6]S
Bg"b,&/^u
public void setSFileName(String value) 4B<D.i ;}
{ g*b%
sFileName = value; %$Wt"~WE"O
} '-4);:(^
IJs*zzR
PsEm(.z
public int getNSplitter() !0fpD'f!n
{ cA`R~o"
return nSplitter; WA8Qt\Q
} 6WgGewn
jkFS=eonK
>wdR4!x!?
public void setNSplitter(int nCount) `{N0+n
{ #|GP]`YT
nSplitter = nCount; z~A||@4'
} <!Nj2>
} &rorBD 5aj
E3_e~yu&
6*S|$lo9B
/* ^uMy|d
**Utility.java Dvo.yn|kB
*/ W~POS'1
package NetFox; 1V+a;-?
v~?d7p{
IW Lv$bPZ/
public class Utility { tcwE.>5O
)2g\GRg6
9|D!&=8
public Utility() xQ* U9Wt;T
{ )T(xQ2&r4
R4_4FEo
YCj"^RC^
} ?2 u_E "
0J7[n*~
//线程睡眠 4G;+ETp
public static void sleep(int nSecond) Fm`hFBKW
{ >E#| H6gx
try{ pOyM/L
Thread.sleep(nSecond); zM|d9TS
} =mn)].Wg
catch(Exception e) 6U @3 xU`
{ 7;5?2)+=6
e.printStackTrace (); r'7;:
} X<x"\Yk
} ipQJn_:2
* Od_Cl
//日志 Agl5[{]E
public static void log(String sMsg) !qV{OXdrB
{ gLsl/G
System.err.println(sMsg); zg.'
} Kg VLXI6
(Vf&,b@U_
T8GxoNm
public static void log(int sMsg) 0<>I\UN0b
{ T@U_;v|rf
System.err.println(sMsg); x4CrWm
} L oe!@c
} o*_[3{FU
^W eE%"
al F*L
/* GLB7h9>
**TestMethod.java 6Hi3h{
*/ jJQ6]ucwa
package NetFox; "6['!rq0
_'ltz!~
pZ/x,b#.
public class TestMethod { 7 }4T)k(a
C;0H _
4rO07)~l
public TestMethod() >DBaKLu\
{ ///xx/weblogic60b2_win.exe xlp^XT6#
try{ @N7X(@O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >~){KV1~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -;a}'1HOE
SiteFileFetch fileFetch = new SiteFileFetch(bean); $ii/Q:w T"
fileFetch.start(); y1p^ &9U
} "diF$Lj
catch(Exception e){e.printStackTrace ();} `J|bGf#
jX-v9eaA
M`-#6,m3
} J/>Y mi,
jmxjiJKP
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public static void main(String[] args) #~^#%G
{ BD&JbH!(
new TestMethod(); /csj(8^w
} iBVV5 f
} T6=,A }t-
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