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)); V}gP'f07zy
} G<n(\85X
for(int i=0;i<nEndPos.length-1;i++) q)vdDdRe_
{ zmd,uhNc:
nEndPos = nStartPos[i+1]; 4.il4Qqy}i
} X^;[X~g
nEndPos[nEndPos.length-1] = nFileLength; %;ZWYj`]n
} w/_n$hX
} FN jT?*
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!wP|t#Sc9
//启动子线程 hbl%<ItI49
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (1pI#H"f9
for(int i=0;i<nStartPos.length;i++) /Iht,@%E
{ \1|]?ZQ\K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aK>5r^7S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !kCMw%[
nStartPos,nEndPos,i); b-4gHW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZslH2#
fileSplitterFetch.start(); k\->uSU9
} V6l~Aj}/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :'1UX <&B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lO=+V 6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MO}J
nEndPos = " + nFileLength); dQP7CP
// fileSplitterFetch[nPos.length-1].start(); qZw4"&,j$
pkTg.70wU
GjTj..G/
//等待子线程结束 Pf,S`Uw;
//int count = 0; s&(,_34
//是否结束while循环 8/q6vk><
boolean breakWhile = false; j7r!N^
$p_FrN{
[4qCW{x._
while(!bStop) j{}-zQ]n
{ A8Z2o\+
write_nPos(); Cwo(%Wc
Utility.sleep(500); 9{&APxm
breakWhile = true; },1**_#<Br
vn oI.;H,
0LI:R'P+P[
for(int i=0;i<nStartPos.length;i++) [f`^+,U
{ @ qFE6!
if(!fileSplitterFetch.bDownOver) K&1o!<|
{ u=j|']hp#&
breakWhile = false; 2hB';Dv
break; Mou@G3
} +Smt8O<N
} Q2^~^'Yk
if(breakWhile) YA(_*h
break; <(|No3jx
}m '= _u
oh%kuO T[
//count++; $E=t6WvA
//if(count>4) aJh=4j~.
// siteStop(); x0t&hY>P!
} [s1Hd~$
D@]gc&JN[
VyRU_<xP
System.err.println("文件下载结束！"); ZHPsGHA
} TTNgnP
catch(Exception e){e.printStackTrace ();} -KzU''
} /cmnX'z
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_W@SCV)yH
//获得文件长度 7lP3\7wD@9
public long getFileSize() fwR3=:5~
{ /t"p^9!^
int nFileLength = -1; JGmW>mH
try{ M:m-iX
URL url = new URL(siteInfoBean.getSSiteURL()); [,GXA)j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9ICC2%j|
httpConnection.setRequestProperty("User-Agent","NetFox"); fX.V+.rj
]>utLi5dX
ZqI.n4:9
int responseCode=httpConnection.getResponseCode(); x.>E7 +
if(responseCode>=400) >{DHW1kF?
{ .3;bUJ1
processErrorCode(responseCode); @G/':N
return -2; //-2 represent access is error $}[Tj0+:
} P1PP#>E-2
Salu[)+?
[\9WqHs
String sHeader; E\M{/.4 4
DNgQ.lV
1[k~*QS
for(int i=1;;i++) 9JF*xXd>Q
{ id^U%4J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2>{_O?UN
//Utility.log(in.readLine()); \L#BAB6z
sHeader=httpConnection.getHeaderFieldKey(i); uj.~/W1,!
if(sHeader!=null) #=WDJT:
{ V/j]UK0$
if(sHeader.equals("Content-Length")) a S- rng
{ dEXHd@"H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pn{yk`6E
break; -KRHcr \
} @5gZK[?|I
} ?FRR";
else Y^dVNC3vd
break; T7;)HFGeW
} m8rz i:
} 7R\!'`]\M
catch(IOException e){e.printStackTrace ();} N0s)Nao4
catch(Exception e){e.printStackTrace ();} vcB+h;x
&`rV{%N"
-`e=u<Y9@
Utility.log(nFileLength); 0/.#V*KM
"?j|;p@!>
>Kl78w:
return nFileLength; %EPqJ(T
} *$(=I6b
p71%-nV
?o0#h
//保存下载信息（文件指针位置） dRZor gar
private void write_nPos() XEqg%f
{ S(A0),
try{ i_GE9A=h
output = new DataOutputStream(new FileOutputStream(tmpFile)); A>L(#lz#ek
output.writeInt(nStartPos.length); Fqzk/m
for(int i=0;i<nStartPos.length;i++) JxQwxey{
{ oB[3?e
// output.writeLong(nPos); <$.KCLP
output.writeLong(fileSplitterFetch.nStartPos); 4Uz:zB
output.writeLong(fileSplitterFetch.nEndPos); #e%.z+7I
} aMTY{
output.close(); ]P0DPea
} <.3@-z>w2,
catch(IOException e){e.printStackTrace ();} tC+9W1o
catch(Exception e){e.printStackTrace ();} b*Ipg8n+
} k?Jzy
(2@b ,w^
4qda!%
//读取保存的下载信息（文件指针位置） 4x'^?0H@
private void read_nPos() 1elx~5v1.=
{ =nnS X-x
try{ yh_s(>sh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I#l9
int nCount = input.readInt(); ,Ucb)8a
nStartPos = new long[nCount]; qn@Qd9Sf
nEndPos = new long[nCount]; 7kn=j6I
for(int i=0;i<nStartPos.length;i++) {CH\TmSz
{ kt1f2cj
nStartPos = input.readLong(); whKr3)
nEndPos = input.readLong(); P7\(D`
} kSNVI-Wzu
input.close(); se_zCS4Y
} ^F?H)[0
catch(IOException e){e.printStackTrace ();} _0F6mg n
catch(Exception e){e.printStackTrace ();} IJ,,aCj4g
} MbnV5b:X
zi>f436-
~s^&*KaA
private void processErrorCode(int nErrorCode) [ur/`
{ mC~W/KReA
System.err.println("Error Code : " + nErrorCode); c%~'[W04\
} {yyg=AMz
svpWABO
! # tRl
//停止文件下载 ECkfFE`
public void siteStop() |0f\>X I
{ @7lZ{jV$
bStop = true; jZv8X5i
for(int i=0;i<nStartPos.length;i++) s*k"-5
fileSplitterFetch.splitterStop(); \g4\a?i
&s/aJgJhp
|r-<t
} =X&h5;x'
} V2/+SvB2
//负责部分文件的抓取 6lT'%ho}B
**FileSplitterFetch.java N83RsL "}_
*/ ]VJcV.7`
package NetFox; !+)$;`
`*oLEXYN
n^Z?u9VR
import java.io.*; ;8 McG83
import java.net.*; 4kXx(FE
1Y9Ye?~jd
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public class FileSplitterFetch extends Thread { M~662]Ekk
OD1ns
jMp{
String sURL; //File URL b!.# `.
long nStartPos; //File Snippet Start Position G|O"Kv6
long nEndPos; //File Snippet End Position W>@%d`>o5
int nThreadID; //Thread's ID L0&!Qct
boolean bDownOver = false; //Downing is over V$v;lvt^Uq
boolean bStop = false; //Stop identical M2xUs
FileAccessI fileAccessI = null; //File Access interface bkOm/8k|4
5 #kvb$97
!d(!1fC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g<.8iW 'c
{ |e< U%v
this.sURL = sURL; It_yh #s
this.nStartPos = nStart; t*}<v@,
this.nEndPos = nEnd; 8=nm`7(]
nThreadID = id; }p- %~Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JAiV7v4&R
} ;,4J:zvZdQ
kT$4X0}
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public void run() SiBbz4
{ 3:;%@4f
while(nStartPos < nEndPos && !bStop) b6/:reH{
{ I(7gmCV
/Cg/Rwl
e1/|PgT(KM
try{ L0_=R;.<
URL url = new URL(sURL); dJ&s/Z/>E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >y8Z{ALQ5
httpConnection.setRequestProperty("User-Agent","NetFox"); 3o^V$N.
String sProperty = "bytes="+nStartPos+"-"; 57MoO
httpConnection.setRequestProperty("RANGE",sProperty); ?=4t~\g?
Utility.log(sProperty); &YMVoyVD
Y-{spTI
WI~%n
InputStream input = httpConnection.getInputStream(); VmT5?i
//logResponseHead(httpConnection); ^X;>?_Bk
a0LX<}
"Q J-IRt&
byte[] b = new byte[1024]; '+QgZ>q"
int nRead; #xo&#FIH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (@#Lk"B
{ +es6c')
nStartPos += fileAccessI.write(b,0,nRead); ut,"[+J
//if(nThreadID == 1) L%8"d6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); plIx""a^h
} 'K"*4B^3
QA9vH'
z"vgwOP su
Utility.log("Thread " + nThreadID + " is over!"); >5gzo6j/
bDownOver = true; 6FmgK"t8
//nPos = fileAccessI.write (b,0,nRead); 2bC%P})m
} PJ.jgN(r
catch(Exception e){e.printStackTrace ();} pxC5a i
} f 0#V^[%Q
} ^R$dG[Qf
DtN6.9H2`
!'MD8
//打印回应的头信息 nc{<v
public void logResponseHead(HttpURLConnection con) hWu)0t
{ 3gh^a;uC
for(int i=1;;i++) OlJj|?z$
{ ]a%Kn]HI&2
String header=con.getHeaderFieldKey(i); N~kYT\$b#
if(header!=null) P3|<K-dFAK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +]zP $5_e
Utility.log(header+" : "+con.getHeaderField(header)); '[E_7$d
else xr2:bu
break; vJ' 93h
} LYFvzw>M
} -XyuA:pxx
H}~^,B2;
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public void splitterStop() *Wau7
{ M:$nL
bStop = true; }.vy|^X
} s#fmGe"8
9|m L
Z}C%%2Iz
} :F\f}G3
E;Hjw0M'k
{cI<4><
/* Ye6O!,R
**FileAccess.java *~L]n4-
*//文件访问(定位，写) t*#&y:RG
package NetFox; I$LO0avvH2
import java.io.*; jY.%~Y1y
e-CW4x
eH8.O
public class FileAccessI implements Serializable{ jYF3u0 )
iT"Itz-^#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AVWrD[ wD2
RandomAccessFile oSavedFile; J#]yKgT
long nPos; 4\3t5n
jayoARUB
:<gk~3\
public FileAccessI() throws IOException GZt] 38V)g
{ Jx<
this("",0); -tdG}Gu
} wp*1HnWj8Y
( -@>
do,X{\
public FileAccessI(String sName,long nPos) throws IOException y|se^dn
{ Hdx|k=-Q^
oSavedFile = new RandomAccessFile(sName,"rw"); Z(eSnV_RL
this.nPos = nPos; NZ5~\k
oSavedFile.seek(nPos); nE;gM1I
} ?OyW|jL
(c2\:hvy
3lN+fQ>)S
public synchronized int write(byte[] b,int nStart,int nLen) Gp+XM
{ U;@jl?jnG
int n = -1; Se`N5hQ
try{ oUSG`g^P(M
oSavedFile.write(b,nStart,nLen); ^ym{DSx
n = nLen; ^aCYh[=
} WRyLpTr-
catch(IOException e) J.l%HU
{ a)Ek~{9
e.printStackTrace (); nW_
} ~2431<YV
PEIr-qs%D
dDbC0} x/
return n; T7~v40jn|
} AUde_1hi
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"r"An"
} ~7a BeD
&7&*As
6DW|O<k^j
/* R <\Yg3m8
**SiteInfoBean.java 9m4rNvb
*/ Wp3l>:
package NetFox; SGd.z6"H
pe})A
Q{hOn]"
public class SiteInfoBean { n0pe7/Ai
VBJ]d|
, ~X;M"U
private String sSiteURL; //Site's URL qu+2..3
private String sFilePath; //Saved File's Path TWEqv<c
private String sFileName; //Saved File's Name ;@ X
private int nSplitter; //Count of Splited Downloading File J*X.0&Toc
J9.p8A^^2
E(_I3mftm
public SiteInfoBean() ! hr@{CD
{//nSplitter的缺省值为5 (Nb1R"J`
//default value of nSplitter is 5 >L`mF_WG
this("","","",5); ;_5 =g
} ~HRWKPb
3yB6]U
#!,`EU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p|V1Gh<
{ ZMg9Qt
sSiteURL= sURL; 7`@?3?
sFilePath = sPath; 0\nhg5]?
sFileName = sName; 5yi q#
this.nSplitter = nSpiltter; .@-]A
89=JC[c
'|N4fbZd
} IFofFXv_
O>5u5n
NOp=/
public String getSSiteURL() u>6/_^iq
{ 1>x@1Mo+K
return sSiteURL; `f+g A
} `1<3Hu_
x>"JWD
-L?% o_
public void setSSiteURL(String value) 8z8SwWS?
{ .OS?^\
sSiteURL = value; )}\@BtcjA]
} )ZyuF(C&
VhIIW"1
gD+t'qg$
public String getSFilePath() 59BHGvaF
{ c$:=d4t5$
return sFilePath; Pt0}9Q
} (G%gVk]
[Ms{J!^q
WTv\HI2X !
public void setSFilePath(String value) I jztj
{ i=H>D
sFilePath = value; H6S vU
} gs8@b5 RSb
9Sl|l.;!
SH$cn,3F8
public String getSFileName() `oRs-,d|<
{ 8yz((?LrDh
return sFileName; ff./DMDafI
} cBR8HkP~
(DP9& b
MGyB8(
public void setSFileName(String value) Is6 _
{ l@/kPEh
sFileName = value; aC Lg~g4
} y&=19A#
[Pc[{(
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public int getNSplitter() o/9LK
{ 53*, f
return nSplitter; 7RC096 ?}
} Il`k]XM
EQOP?>mWx!
p't:bR
public void setNSplitter(int nCount) 4FE@s0M,
{ >AX~c jo
nSplitter = nCount; ;(0$~O$3u
} AD%D ,l
} bKMR7&e.Ep
~TFYlV
bd P,Zqd
/* ?&<o_/`-H5
**Utility.java c[RLYu
*/ a(DZGQ-as
package NetFox; Y{2d4VoW6
`CEj 4
=>ztBw\
public class Utility { <CKmMZ{
OC>_=i$'
U;Ll.BFP
public Utility() grxl{uIC8
{ P:, x?T?J^
T\ }v$A03
?-::{2O)
} LSu^#B
>"<k8wn
//线程睡眠 46P6Bwobh
public static void sleep(int nSecond) 69j~?w)^
{ &<|-> *v
try{ FJ(B]n[>
Thread.sleep(nSecond); [aM'
} oBNX8%5w
catch(Exception e) K7xWE,y
{ YyJ{
e.printStackTrace (); 'tu@`7*
} /sT ^lf=
} 4,F3@m:<
Cq*}b4^;
//日志 9kX=99kf[
public static void log(String sMsg) =e!l=d|/
{ )dIfr
System.err.println(sMsg); g?[&0r1
} Ph+X{|
z(` }:t
bA<AG*
public static void log(int sMsg) r -q3+c^+
{ iA3>X-x
System.err.println(sMsg); W\qLZuQ
} {`H<=h__
} M9s43XL(&
I' ! r
$~,}yh;
/* ]C ~1]7vb
**TestMethod.java bH\C5zt6(
*/ mYh5#E41J
package NetFox; :`Uyn!w
oO#xx)b
mo;)0Vq2l
public class TestMethod { p>:ef<.i
G=Hf&l
)b&-3$?
public TestMethod() GT'7,+<?N
{ ///xx/weblogic60b2_win.exe Zv|p>q`R2
try{ 0939i_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hH1lgc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EzIs@}
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2T@L{ql
fileFetch.start(); 1O7]3&L@
} 0Ws;|Yg
catch(Exception e){e.printStackTrace ();} :/v,r=Y9p
```d:f
1X::0;3
} 7k]RO
?AnjD8i
2<'`^AO@
public static void main(String[] args) e`Co,>W/
{ ?jri!]ux#
new TestMethod(); *!g 24
} /BMtcCPG!
} ms}f>f=
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