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)); JAK+v
} f2JeXsOI
for(int i=0;i<nEndPos.length-1;i++) &ZRriqsQg
{ Nx8~Rn
nEndPos = nStartPos[i+1]; ~P47:IZf
} \NEXtr`Th
nEndPos[nEndPos.length-1] = nFileLength; jx3J$5
} cBO.96ZHE
} &pCNOHi|
6tPgFa#N
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//启动子线程 )r)3.|wJm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H40~i=.
for(int i=0;i<nStartPos.length;i++) 7( &\)qf=n
{ 5VU 5kiCt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E8Jy!8/X9T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?J<V-,i
nStartPos,nEndPos,i); .FarKW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l1&NU'WW
fileSplitterFetch.start(); ;w/|5 ;{A;
} NT^m.o~4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LB1AjNJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YQ&Ww|xe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5p.vo"7
nEndPos = " + nFileLength); KZ"&c~[
// fileSplitterFetch[nPos.length-1].start(); <QUjhWxDb
+ti_?gfx
}W:Rg}v
//等待子线程结束 @MS}tZ5
//int count = 0; SpM|b5c5
//是否结束while循环 xb2xl.2x!
boolean breakWhile = false; KkIxtFM
g/o@,_
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while(!bStop) J 8z|ua
{ "h-G=vo,kl
write_nPos(); <}@*i
Utility.sleep(500); XA&Vtgu
breakWhile = true; 6`tc]a"#Zb
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,:I:F
for(int i=0;i<nStartPos.length;i++) vqC!Ajm
{ U.fLuKt
if(!fileSplitterFetch.bDownOver) 5 (Lw-_y#
{ _</>`P[
breakWhile = false; *kmD/J
break; m~[4eH,
} i;u#<y{E
} *Vbf;=Mb
if(breakWhile) VO (KQx
break; }=dUASL
&%@b;)]J
B#>7;xy>
//count++; Y ,Iv<Hg
//if(count>4) \F$Vm'f_
// siteStop(); r9nyEzk
} " vW4"R6
LFzL{rny!U
-W/Lg5eK
System.err.println("文件下载结束！"); b9F:X
} i#&iT P`
catch(Exception e){e.printStackTrace ();} r%craf
} I`$"6 Xy
ma +iIt;
Y<4%4>a
//获得文件长度 -x~4@~
public long getFileSize() WE-cq1)
{ s?fO)7ly
int nFileLength = -1; +f}u.T_#
try{ 0tL#-47
URL url = new URL(siteInfoBean.getSSiteURL()); 9BZyCz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FO"sE`
httpConnection.setRequestProperty("User-Agent","NetFox"); Qj1qx;S
&V`~ z e
ftr8~*]O
int responseCode=httpConnection.getResponseCode(); 9+"R}Nxv^
if(responseCode>=400) ~`xaBz0q
{ gMGX)Y ,=/
processErrorCode(responseCode); AYVkJq?
return -2; //-2 represent access is error I"=a:q
} qG]G0|f
$?HOke
n A<#A
String sHeader; F}f/cG<X
c'wxCqnE
Y<]A5cm
for(int i=1;;i++) w$aiVOjgT
{ X6T*?t3!9[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8_d>=*(
//Utility.log(in.readLine()); dR9[K4`p/
sHeader=httpConnection.getHeaderFieldKey(i); m]7oTmS
if(sHeader!=null) n$*e(
{ 4x2 ;@Pd
if(sHeader.equals("Content-Length")) !08\w@
{ T5AoBUw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KW&vX%i(.
break; G~VukW<e
} \y7kb
} ;kX:k~,]}>
else fn~Jc~[G|
break; m,Fug1+N
} F['<;}
} 8l50@c4UF~
catch(IOException e){e.printStackTrace ();} `y^tCJ2u*
catch(Exception e){e.printStackTrace ();} .|VWYN
Knjg`f
u ? }T)B
Utility.log(nFileLength); *_ U=KpZF
R7 WGc[
"PK`Ca@`v
return nFileLength; |z+K]R8_
} sTb@nrRxH
oEuV&m|yX
fF|m~#y
//保存下载信息（文件指针位置） 4Odf6v,*@
private void write_nPos() ,S%DHT
{ vNA~EV02
try{ =SUCcdy&
output = new DataOutputStream(new FileOutputStream(tmpFile)); a(s%3"*Q
output.writeInt(nStartPos.length); U WU PY
for(int i=0;i<nStartPos.length;i++) mu>L9Z~(L_
{ O$K?2-
// output.writeLong(nPos); @hG]Gs[,o
output.writeLong(fileSplitterFetch.nStartPos); 0ECQ>Ux:
output.writeLong(fileSplitterFetch.nEndPos); C)RJjaOr
} j1sgvh]D
output.close(); 'KU)]v
} *}Cm/li/w
catch(IOException e){e.printStackTrace ();} <CIy|&J6
catch(Exception e){e.printStackTrace ();} @((Y[<
} mC,:.d
2Sha&Z*CE
&x#3N=c#
//读取保存的下载信息（文件指针位置） iiWm>yy
private void read_nPos() yQ/E0>Uj!
{ DOa%|H'P
try{ ?kBX:(g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B=;pwX
int nCount = input.readInt(); 7xlarns
nStartPos = new long[nCount]; v6#i>n~x,
nEndPos = new long[nCount]; qJyGr ?
for(int i=0;i<nStartPos.length;i++) "?f_U/+D<
{ jg3X6/'
nStartPos = input.readLong(); z7PmyU >
nEndPos = input.readLong(); q(nPI
} 0+m4 }]6l
input.close(); {I9<W'k{
} i\yp(tE%^
catch(IOException e){e.printStackTrace ();} _KSlIgQ }0
catch(Exception e){e.printStackTrace ();} @@QB,VS;{<
} ol#4AU`
so]p1@K
"P9SW?',
private void processErrorCode(int nErrorCode) W02t6DW
{ +DR,&;
System.err.println("Error Code : " + nErrorCode); _C&XwCIm
} r1R\cor
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[izP1A$r#Q
//停止文件下载 ()`cW>[
public void siteStop() 7+c}D>/`:
{ Ce.*yO<-
bStop = true; pLtAusx
for(int i=0;i<nStartPos.length;i++) hVLVMqd
fileSplitterFetch.splitterStop(); 0V!@*Z
1m\ihU
p8bAz
} |3K]>Lio
} J*zm*~8\
//负责部分文件的抓取 |k[hk
**FileSplitterFetch.java hha!uD~(
*/ T{B\1|2w
package NetFox; J!"#N}[
<%ZlJ_cM
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import java.io.*; CeD(!1VG
import java.net.*; v;$cx*?
;>jLRx<KC
#}8 x
public class FileSplitterFetch extends Thread { [`/d$V!e
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!IAd.<,
String sURL; //File URL yGZsPQIaV
long nStartPos; //File Snippet Start Position /~6)Vt
long nEndPos; //File Snippet End Position dkI(&/
int nThreadID; //Thread's ID d:GAa
boolean bDownOver = false; //Downing is over m1{OaHxKh
boolean bStop = false; //Stop identical y-R:-K XH=
FileAccessI fileAccessI = null; //File Access interface JXKo zy41
me`|i-
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NxzRVsNF
{ mJFFst,
this.sURL = sURL; /vrjg)fer
this.nStartPos = nStart; J,,+JoD
this.nEndPos = nEnd; D]B;5f
nThreadID = id; |*te69RX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5 cz6\A&
} 97-=Vb
3uJ>:,~r
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public void run() 5lYzgt-oP
{ .~Y% AI
while(nStartPos < nEndPos && !bStop) r;'Vy0?AL
{ 1Uf8ef1,
m>8tA+K)+)
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try{ ,mm9X\ '
URL url = new URL(sURL); Ps=<@,dks
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0{Bhr12V
httpConnection.setRequestProperty("User-Agent","NetFox"); 6eq`/~#
String sProperty = "bytes="+nStartPos+"-"; c,FhI~>R
httpConnection.setRequestProperty("RANGE",sProperty); D4;6}gRC
Utility.log(sProperty); eczS(KoL4
h$#zuqm
g'nN#O
InputStream input = httpConnection.getInputStream(); wfY]J0l
//logResponseHead(httpConnection); ,`.`}'
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a,~}G'U
byte[] b = new byte[1024]; n}!D)Gx
int nRead; 03^?+[C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e}bY9
{ r>.^4Z@
nStartPos += fileAccessI.write(b,0,nRead); Y&y5^nG
//if(nThreadID == 1) 6fcn(&Qk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [&H?--I
} S1G=hgF_L
OYwH$5
ns;nle|m
Utility.log("Thread " + nThreadID + " is over!"); g4=6\vg
bDownOver = true; &Rxy]kBA
//nPos = fileAccessI.write (b,0,nRead); lgei<\6~n5
} g4CdzN~
catch(Exception e){e.printStackTrace ();} xjO((JC
} s\dhQZw3
} QJKVNOo
m~U2L
UCDvN
//打印回应的头信息 I15g G.)
public void logResponseHead(HttpURLConnection con) L; f
{ }5{#f`Ca6
for(int i=1;;i++) 9G)q U
{ `|d&ta[{
String header=con.getHeaderFieldKey(i); ?> SH`\
if(header!=null) o:C],G_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DX)T}V&mP
Utility.log(header+" : "+con.getHeaderField(header)); 3|g]2|~w@h
else mbCY\vEl
break; 2%oo.?!R
} m(c5g[6nO
} e Zb8x
*3r{s'm
Kl)PF),
public void splitterStop() $IB>a
{ Tx!c}
bStop = true; 2 bQC2
} ~e@pL*s
~.'NG? %7P
]&kzIxh
} a}]zwV&
|=CV.Su
)s';m$
/* _8G
**FileAccess.java Nq3q##Ut:
*//文件访问(定位，写) Axtf,x+lH
package NetFox; ?[K\X
import java.io.*; beM}({:`
{V)Z!D
Tfba3+V
public class FileAccessI implements Serializable{ 3#@ETt0X(
-{A!zTw1w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nS}XY
RandomAccessFile oSavedFile; D; 0iNcit
long nPos; Wi?37EHr
T;u>]"S
^KsiTVY
public FileAccessI() throws IOException 1Lf:TQB
{ =Qcz:ng
this("",0); J}-,!3qxW
} j+c<0,Kj
^|(w)Sy
N?'V,p 0=
public FileAccessI(String sName,long nPos) throws IOException u}7#3JfLn
{ B0^0d*8t|@
oSavedFile = new RandomAccessFile(sName,"rw"); B0KZdBRx}
this.nPos = nPos; mt+IB4`
oSavedFile.seek(nPos); 0O,l rF0'
} 4ZK8Y[]Lv
wM;9plYlw0
,ij"&XA
public synchronized int write(byte[] b,int nStart,int nLen) 45hjN6
{ poqx O
int n = -1; Jz!8Xg%a
try{ n~#%>C7
oSavedFile.write(b,nStart,nLen); hK+Iow-
n = nLen; P>dMET
} hoc$aqP6pp
catch(IOException e) <Cvlz^K[
{ H-9%/e
e.printStackTrace (); Q`Q%;%t
} tBp146`
GB(o)I#h
Ua^'KRSO
return n; lglC1W-q
} R^.oM1qu|
=-`}(b2N
*:q3<\y{
} pN)9GO5
@eRR#S
l!plw,PYC
/* D-/K'|b
**SiteInfoBean.java 6BihZ|H04
*/ X;7gh>Q'4
package NetFox; &cSTem 0
4dXuy>Km
2z7+@!w/
public class SiteInfoBean { );wSay>%(
^1vh5D
?=B$-)/
private String sSiteURL; //Site's URL C|"h]
private String sFilePath; //Saved File's Path gp:,DC?(
private String sFileName; //Saved File's Name Y{TzN%|LV
private int nSplitter; //Count of Splited Downloading File m ?a&XZ
Uj)~>V'
&k /uR;yw
public SiteInfoBean() XHgwK@GU
{//nSplitter的缺省值为5 y#:_K(A" k
//default value of nSplitter is 5 krPwFp2[*
this("","","",5); )QGj\2I
} c|lo%[]R!
6uCa iPV
&+\J "V8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yVvO!
{ [a;U'v*
sSiteURL= sURL; J~6+zBF
sFilePath = sPath; OAMsqeWYA
sFileName = sName; ,~-"EQT
this.nSplitter = nSpiltter; GqXnOmk
>;eWgQ6V
aU,Zjm7fp
} (c ?OcwTH
\f6SA{vR|
%vvA'WG
public String getSSiteURL() I @TR|
{ c rPEr
return sSiteURL; ~F^(O{EG
} QAigbSn]
G[1:<Vg8
sr+* q6W
public void setSSiteURL(String value) Q# w`ZQX3
{ _-$"F>
sSiteURL = value; lCBb0k2
} cF9bSY_Eh
%|$h<~
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public String getSFilePath() GndU}[0J
{ pe>R2<!$
return sFilePath; =EI>@Y"
} V(mz||'*
(+d7cln
5o 4\Jwt
public void setSFilePath(String value) D<5;4Mb
{ FUic7>
sFilePath = value; =T'N6x5@
} NGIbUH1[
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fr$E'+l)
public String getSFileName() }{Ab:+aNd
{ #Hl0>"k ,
return sFileName; =&RpW7]
} ;*^2,_
5qzFH,
.}n%gc~A
public void setSFileName(String value) 0b%"=J2/p.
{ {3F;:%$`c
sFileName = value; 45` i
} ~0"(C#l9
jj2 [Zh/h
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public int getNSplitter() n4;
{ '\8gY((7
return nSplitter; W($}G_j[B1
} 4RCD<7
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h.PVRAwk
public void setNSplitter(int nCount) `)Z"||8K
{ J jRz<T;
nSplitter = nCount; f%fD>a
} `yYoVu*
} U.]5UP:a
-`nQa$N-
xE.K
/* NUBf>~_}
**Utility.java -j1?lY
*/ Vmq:As^a
package NetFox; \$GM4:R D
mw2/jA7
]X y2km]
public class Utility { q1!45a
{cmY`to
<d89eV+
public Utility() ~9%L)nC2'
{ )Il) H
28,Hd!{
VfWU-lJ
} /J''`Tf
LpCJfQ
//线程睡眠 KE>|,Ur
public static void sleep(int nSecond) v_M-:e3`
{ xQLVFgd
try{ @r7ekyO8)
Thread.sleep(nSecond); /Kcp9Qx
} e ]-fb{oVH
catch(Exception e) |q0F*\z3
{ X{cFqW7
e.printStackTrace (); D6X0(pU0
} D%[yAr;r
} mX8k4$z
.[mI9dc
//日志 ?8AV-rRX
public static void log(String sMsg) v@m2c_,
{ Rq`B'G9|c
System.err.println(sMsg); O5X@'.#rU
} in}d(%3h
%gBulvg
:wWPEhK
public static void log(int sMsg) lICpfcc(+
{ $K& #R-
System.err.println(sMsg); X#v6v)c
} }eKY%WU>O
} TS2zzYE6Z
tqok.h
0iS"V^aH
/* M N-j$-y}
**TestMethod.java s=KK)6T
*/ olA 1,8
package NetFox; dWKjVf
fHFy5j0H
w?eJVi@w{
public class TestMethod { eMT}"u8$A
JSp V2c5Q
J}zN]|bz
public TestMethod() \S5YS2,P
{ ///xx/weblogic60b2_win.exe {$ a $m
try{ -_`dA^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oItEGJ|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <GdQ""X
SiteFileFetch fileFetch = new SiteFileFetch(bean); %Z.!T
fileFetch.start(); yj<j>JtN
} mFk6a{+YX
catch(Exception e){e.printStackTrace ();} "UM*(&
YRU1^=v
(~k{aO
} |$^a"Yd`9
BYuoeN!
^RIDC/B=V6
public static void main(String[] args) s?Wkh`b
{ ^ "D
new TestMethod(); ;\mTm;]G
} %DQ!#Nl*
} `4Db( ~
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