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)); o`EL)K{
} <-3_tu>l
for(int i=0;i<nEndPos.length-1;i++) Z~WUILx,
{ `'gadCTb=
nEndPos = nStartPos[i+1]; QL{^
} B0&W wa:
nEndPos[nEndPos.length-1] = nFileLength; |Qa[N(
} <q dM
} {dk%j~w8
I8%2tLVY
bt2`elH|
//启动子线程 L)!9+!PKD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AD=qB5:
for(int i=0;i<nStartPos.length;i++) HuCzXl
{ VD).UdUn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DNu^4#r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ([+u U!
nStartPos,nEndPos,i); $vQ#ah/k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |oL}c!0vs
fileSplitterFetch.start(); .8I\=+Zi
} T*'?;u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %~$P.Zh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w:0=L`<Eu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jIOrB}
nEndPos = " + nFileLength); x U1](O
// fileSplitterFetch[nPos.length-1].start(); ux 7^PTgcO
Te:4z@?
L]_1z
//等待子线程结束 1lf5xm.
//int count = 0; 6[{|'
//是否结束while循环 q!sazVaDp
boolean breakWhile = false; =D@+_7\?
6y4&nTq[
&E(KOfk#
while(!bStop) ^#Ruw?D
{ n!Dy-)!`O
write_nPos(); IL\2?(&Z
Utility.sleep(500); 1J tt\yq
breakWhile = true; r*gQGvc
(/oHj^>3N`
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for(int i=0;i<nStartPos.length;i++) {imz1g;
{ H fg2]N
if(!fileSplitterFetch.bDownOver) HF\|mL
{ h>A~..
breakWhile = false; 5Lo\[K>j
break; X`n)]~
} v"po}K
} Ew9\Y R}
if(breakWhile) R[l9f8
break; .>.B
NukcBH
.0[ zZ
//count++; x bsk
//if(count>4) 8^8fUN4<=
// siteStop(); 2(<2Gnpl
} !pwY@}oL
bIR&e E
04u^Q
System.err.println("文件下载结束！"); Yr\pgK,
} WLB@]JvTBY
catch(Exception e){e.printStackTrace ();} *T+Bjj;w
} ^Qx qv
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{4%B^+}T
//获得文件长度 LMF@-j%
public long getFileSize() )rqb<O
{ bu j}pEI
int nFileLength = -1; M`~UH\
try{ ;nDCyn4i]
URL url = new URL(siteInfoBean.getSSiteURL()); "Q>gQKgL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LxcC5/@\~(
httpConnection.setRequestProperty("User-Agent","NetFox"); VD,p<u{r
PGE|){ <
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int responseCode=httpConnection.getResponseCode(); V^
if(responseCode>=400) Xqz\%&G
{ R[%ZyQ_
processErrorCode(responseCode); Ep.Q&(D >
return -2; //-2 represent access is error ~eVq Fc
} Ui^~A
zn=Ifz)#|
YEg(QOn3Q
String sHeader; 19r4J(pV
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3t*e|Ih&j5
for(int i=1;;i++) 1hz:AUH
{ H;eGBVi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g ss 3e&
//Utility.log(in.readLine()); L355uaj
sHeader=httpConnection.getHeaderFieldKey(i); IO*}N"
if(sHeader!=null) t,f)!D$
{ "$lE~d">
if(sHeader.equals("Content-Length")) s5 P~feg
{ .:`+4n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7;wx,7CUq
break; OIqisQ7ZB
} CXe2G5
} C`++r>
else _gGI&0(VM
break; gq'}LcV
} ;VLv2J*
} e\[z Q 2Z3
catch(IOException e){e.printStackTrace ();} E/OJ}3Rf
catch(Exception e){e.printStackTrace ();} -$; h+9BO
b,k%n_&n
rmzM}T\20
Utility.log(nFileLength); Ub(8ko:8$
nQ$4W
m,u5S=3A{!
return nFileLength; S m%\,/3
} +p:?blG
(D?%(f
4F-r}Fj3
//保存下载信息（文件指针位置） MKnG:)T<?l
private void write_nPos() O]XdPH20
{ n' XvPV|
try{ D^[}:O{
output = new DataOutputStream(new FileOutputStream(tmpFile)); C0eqCu)Q
output.writeInt(nStartPos.length); YV6@SXy
for(int i=0;i<nStartPos.length;i++) "<e<0::
{ E!,+#%O>
// output.writeLong(nPos); B5nzkJV<X
output.writeLong(fileSplitterFetch.nStartPos); qG=>eRR
output.writeLong(fileSplitterFetch.nEndPos); 9L"Z ~CUL
} wa#$9p~Q
output.close(); fpDx)lQ
} #]~l]Eq
catch(IOException e){e.printStackTrace ();} &8##)tS(y
catch(Exception e){e.printStackTrace ();} Y/3CB
} tfSY(cXg'T
&EELq"5K
<3 b|Sk:T
//读取保存的下载信息（文件指针位置） 'T '&OA
private void read_nPos() $RFy9(>
{ R>r@I_
try{ t,YnweH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cJ}J4?
int nCount = input.readInt(); -=tf)
nStartPos = new long[nCount]; )r9lT*z
nEndPos = new long[nCount]; \hm;p
for(int i=0;i<nStartPos.length;i++) ']bpsn
{ !zu YO3:
nStartPos = input.readLong(); {c7ZA%T~R
nEndPos = input.readLong(); J$]-)`[G&
} XL`*Tbx
input.close(); 4P>[]~S
} zQ&k$l9
catch(IOException e){e.printStackTrace ();} .tg2HKD_lW
catch(Exception e){e.printStackTrace ();} .IO_&^
} k2"DFXsv
CJDnHuozc
jo7`DDb
private void processErrorCode(int nErrorCode) ;2NJkn9t
{ nB~hmE)
System.err.println("Error Code : " + nErrorCode); _RTJEG
} yFD3:;}
3U_-sMOB|
,n}h_ct
//停止文件下载 ~x!"(
public void siteStop() y@T0 jI
{ Wk0"U V
bStop = true; p)dD{+"/2
for(int i=0;i<nStartPos.length;i++) 3@t&5UjwQ
fileSplitterFetch.splitterStop(); )&nfV5@"
GG9YAu
w$D&LA}(M
} h^H~q<R[T
} v$P<:M M
//负责部分文件的抓取 RS8tE(
**FileSplitterFetch.java q_hkI]
*/ d*Wg>8|
package NetFox; EAdr}io
@hb K
DX*eN"z[
import java.io.*; rz@FUU:&
import java.net.*; $jc&Tk#
dN8@ 0AMSf
LU=<?"N6
public class FileSplitterFetch extends Thread { 75^U<Hz-3{
XBmAD!
)P>}uK;
String sURL; //File URL L/YEW7M
long nStartPos; //File Snippet Start Position 0xSWoz[i6~
long nEndPos; //File Snippet End Position rryC^Vma
int nThreadID; //Thread's ID *ommU(r8
boolean bDownOver = false; //Downing is over 2b[R^O}
boolean bStop = false; //Stop identical z-J?x-<
FileAccessI fileAccessI = null; //File Access interface #835$vOe
37F&s
%u)niY-g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wWaJ%z>3y
{ K[.*8
this.sURL = sURL; o>#ue<Bc6
this.nStartPos = nStart; "B$r{ vG
this.nEndPos = nEnd; =vpXYj
nThreadID = id; d'x'hp%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wa)E.(x
} [!<W{ ($5
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::lD7@Wg
public void run() wT taj08D
{ A#&,S4Wi|
while(nStartPos < nEndPos && !bStop) h&k*i
{ IwTAM9n
" iz'x-wy
k)a3j{{
try{ vg.K-"yQW
URL url = new URL(sURL); |e]2 >NjQa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #77p>zhY
httpConnection.setRequestProperty("User-Agent","NetFox"); y|+n77[Gv
String sProperty = "bytes="+nStartPos+"-"; wqZ*$M
httpConnection.setRequestProperty("RANGE",sProperty); :Sd"~\N+
Utility.log(sProperty); q#6K'=AC
03!!# 5iJ
kdam]L:9
InputStream input = httpConnection.getInputStream(); L]syDn
//logResponseHead(httpConnection); 8F;r$i2
%xJ6t5.-
gdx2&~
byte[] b = new byte[1024]; /}ADV2sF
int nRead; A_ftf7,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }OJ,<!v2pc
{ t=6[FK
nStartPos += fileAccessI.write(b,0,nRead); KkCA*GS
//if(nThreadID == 1) ag7(nn0!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #guq/g$
} $#HPwmd
N!TC}#}l
gQ0W>\xz
Utility.log("Thread " + nThreadID + " is over!"); O 8\wH
bDownOver = true; l>J>?b=x"[
//nPos = fileAccessI.write (b,0,nRead); Q|CLis-
} uQ_s$@brI
catch(Exception e){e.printStackTrace ();} _'.YC<;
} *oW^P~m/
} s (hJ *
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x,+2k6Wn!
//打印回应的头信息 )M:pg%
public void logResponseHead(HttpURLConnection con) zDD1EycH
{ F.DRGi.i
for(int i=1;;i++) n6 VX0R
{ in[yrqFb7t
String header=con.getHeaderFieldKey(i); x3QQ`w-
if(header!=null) bo]= *
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "A>/m"c]*
Utility.log(header+" : "+con.getHeaderField(header)); v?)u1-V0
else Or2J
break; Ibbpy++d[
} Z7Gl^4zn
} .Jvy0B} B
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0c,)T1NG>
public void splitterStop() Vi5&%/Y
{ R|,F C'
bStop = true; DEFh&n
} /+p]VHP\
m|%L[h1
,Qw\w,
} SBbPO5^](
"(QI7:iM
tnn,lWu|
/* zNo(|;19
**FileAccess.java 'y? HF@NJ
*//文件访问(定位，写) KsG>,# Q
package NetFox; sZ7RiH+I
import java.io.*; yaw33/iN
>+3tOv3:
G^6\OOSy
public class FileAccessI implements Serializable{ Cr;d !=
8A,="YIt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t)62_nu
RandomAccessFile oSavedFile; "x"y3v'
long nPos; h{BO\^6x
_ITA$#
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public FileAccessI() throws IOException mKh<M)Bz
{ L>PPAI
this("",0); %(v<aEQtt
} @9}SHS
!vQDPLBL
n#fc=L1U
public FileAccessI(String sName,long nPos) throws IOException WokQ X"
{ k@RIM(^t
oSavedFile = new RandomAccessFile(sName,"rw"); %CaUC'
this.nPos = nPos; I~f8+DE)
oSavedFile.seek(nPos); (F.vVldBy
} jaOt"iU.B
$(PWN6{\r^
zB@@Gs>
public synchronized int write(byte[] b,int nStart,int nLen) OpT0V]k^"9
{ j\^u_D
int n = -1; 1(ud(8?|
try{ OBBEsD/bc
oSavedFile.write(b,nStart,nLen); {R{Io|
n = nLen; i(pevu
} OQC.p,SO
catch(IOException e) 1 xu2$x.b
{ &qP@WFl
e.printStackTrace (); -g6C;<Y
} {W5D)
l*0`{R
A>OGU ^
return n; %J 'RO
} \NN5'DBx
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} wsg u# as|
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I$#)k^Q
/* UN"U#Si)
**SiteInfoBean.java IY=CTFQ8lm
*/ 7lJs{$ P
package NetFox; R8K?!Z
~H+W[r}
S}T*gUO
public class SiteInfoBean { OlJkyL8|
zV<vwIUrr
oP0ZJK&;
private String sSiteURL; //Site's URL -?K?P=B;X
private String sFilePath; //Saved File's Path ?{bAyh/
private String sFileName; //Saved File's Name *wY { ~zh
private int nSplitter; //Count of Splited Downloading File nOE 1bf^l
$[NC$*N7
:+nECk
public SiteInfoBean() z/IZ ;K_e
{//nSplitter的缺省值为5 "VfV;)]|w
//default value of nSplitter is 5 mEM/}]2
this("","","",5); V(LE4P1
} /cN. -lEo%
k.dQ;v}
Ue8k9%qV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,aLdW,<6
{ 0k7kmDW
sSiteURL= sURL; ~=pAy>oV
sFilePath = sPath; #!n"),3
sFileName = sName; +mqz)-x
this.nSplitter = nSpiltter; [61T$.
WV8?zB1
lW8!_h"G`n
} ]PI|Xl
!KEnr`O2u
xqAXfJ.
public String getSSiteURL() ~1`ZPLVG
{ e#uk+]
return sSiteURL; a=!I(50
} n~wNee
L9FijF7
R>YDn|cWI
public void setSSiteURL(String value) .-(s`2
{ 1~x=bphS
sSiteURL = value; JnT1-=t.
} 52L* :|b
(6WSQqp
S/XkxGZ2
public String getSFilePath() !83N. gN
{ I}@m6D|\
return sFilePath; )7j CEA03
} M-B-
Yiq8>|
ji|`S\u#b
public void setSFilePath(String value) H:DTvv8e{
{ mh4`,N
sFilePath = value; tl:+wp7P`
} ~D9VjXfL)
)= ,Lfj8x
#n]js7
public String getSFileName() zK(9k0+s
{ @ T'!;)
return sFileName; (WCpaC
} 1&ZG6#16q
lV]hjt-L 2
lJpD>\$}@R
public void setSFileName(String value) gnlGL[r|
{ A/lxXy}D
sFileName = value; [53rSr
} 73A1+2
l6:k|hrm;
D!Owm&We
public int getNSplitter() Z+' 7c|a
{ BR8z%R
return nSplitter; .<gAa"
} K!7o#"GM
25XD fi75
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public void setNSplitter(int nCount) |t1D8){!
{ ~=aGv%vX
nSplitter = nCount; Q 6{2@
} '=G4R{
} )3=oS1p
xqmP/1=NO
Xnt`7L<L
/* zq80}5%2CT
**Utility.java 6{8qATLR
*/ q*{i/=~
package NetFox; )Uw QsP
:[#HP66[O5
e]!C Aj7uS
public class Utility { P+:FiVj@~
&1ASWllD
2/PaXI/Z
public Utility() ~j^HDHY@
{ T|GRkxd,E3
[(BA:x1
^SpD)O{
} WpP8J1KN[
8b8ui
//线程睡眠 K I
public static void sleep(int nSecond) Mc>]ZAzr
{ 8c3`IIzAS
try{ z'O$[6m6
Thread.sleep(nSecond); ,+3l9FuQ
} F2:+i#lE
catch(Exception e) ;El"dqH
{ M}!7/8HUC
e.printStackTrace (); Wy.2*+5FX0
} Sir7TQ4B
} .M!6${N);
)7<JGzBZ1
//日志 ,}2M'DSWa
public static void log(String sMsg) x|<rt966A
{ J_ ?;On5
System.err.println(sMsg); |eAl!k
} ,@tYD(Z
3v :PBmE
B'"C?d<7
public static void log(int sMsg) S)Sv4Qm
{ .t.H(Q9
System.err.println(sMsg); 3;Kv9i<~LE
} G#ZU^%$M,
} H2 5Mx>|d
ZMids"Xdf
J [J,
/* @QV|<NeH
**TestMethod.java :/c=."z.
*/ PaP47>(
package NetFox; F8$.K*tT
M&Sjo' ( .
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public class TestMethod { C|5eV=f)P
d^ L`dot
r"x|]nvg^
public TestMethod() }o0R`15dA
{ ///xx/weblogic60b2_win.exe i64a]=
try{ ?k<i e2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tH,}_Bp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~>3$Id:
SiteFileFetch fileFetch = new SiteFileFetch(bean); u7ZSs-LuHw
fileFetch.start(); wo5"f}vd#
} v~[=|_{
catch(Exception e){e.printStackTrace ();} $`(}ygmP
" |[w.`
F<Js"z+
} cW4:eh
T~J6(,"
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public static void main(String[] args) ,-myR1}
{ m{9m.~d
new TestMethod(); \< <u
} Bwj^9J/ob
} } 1^/[?
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