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)); 5} |O
} _i~n!v
for(int i=0;i<nEndPos.length-1;i++) d_#\^!9
{ g6EdCG.V
nEndPos = nStartPos[i+1]; XPXC7_fV
} !OM9aITv[
nEndPos[nEndPos.length-1] = nFileLength; g.aNITjP
} Pa2HFy2
} \@nmM&7C!4
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zNRoFz.
//启动子线程 U,)Ngnd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (FZL>
for(int i=0;i<nStartPos.length;i++) ?@Z~i]gE[V
{ 6"WR}S0o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d+~c$(M)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JGt4B
nStartPos,nEndPos,i); hZI9*=`,"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M]!\X6<_
fileSplitterFetch.start(); AC,$(E
} kac@yQD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 94I8~Jj4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TveCy&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (xK=/()}q
nEndPos = " + nFileLength); &q1(v3cOO
// fileSplitterFetch[nPos.length-1].start(); |Z6rP-
x(3E#7>1
`ea;qWy
//等待子线程结束 U jVo "K
//int count = 0; tr7FV1p
//是否结束while循环 %^^2
boolean breakWhile = false; k='sI^lF
btw_k+Fh
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while(!bStop) Jjik~[<q:
{ Eag->mw/~
write_nPos(); \A:m<::
Utility.sleep(500); $y\'j5nk3
breakWhile = true; h3aHCr E
m\U@L+L
+Es3iE @
for(int i=0;i<nStartPos.length;i++) 2|tZ xlt-
{ Cst\_j
if(!fileSplitterFetch.bDownOver) fS-#dJC";`
{ v[CX-CBZ?
breakWhile = false; V!c{%zd
break; 8~:qn@Z|E
} G9z Q{E
} T_6,o[b8
if(breakWhile) 4u X<sJ*
break; m^U\l9LE
9+@_ZI-
_.J{U0N
//count++; "KOLRJ@
//if(count>4) /+2^xEIjE
// siteStop(); =w".B[r
} s?=f,I
Cv{rd##Y8
xex/L%!Rj
System.err.println("文件下载结束！"); y_qFXd
} x_v pds
catch(Exception e){e.printStackTrace ();} VyCBJK
} #1z}~1-
:Ff1Js(Z
q{@>2AlK
//获得文件长度 Gi]Pwo${
public long getFileSize() U;OJ.a9
{ 4&K~EX"^T
int nFileLength = -1; /4w&! $M-
try{ M=26@ n
URL url = new URL(siteInfoBean.getSSiteURL()); r4Pm i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2aW&d=!ZV
httpConnection.setRequestProperty("User-Agent","NetFox"); qB3 SQ:y
qQ/j+
bY+Hf\A
int responseCode=httpConnection.getResponseCode(); HkJ$r<J2
if(responseCode>=400) lj@c"Yrk
{ ff?:_q+.N
processErrorCode(responseCode); #p*{p)]HiA
return -2; //-2 represent access is error l *yml
} +_06{7@h
Th`IpxV
z]=A3!H/Y
String sHeader; zvdtP'&uj
"%<Oadz ap
vov"60K
for(int i=1;;i++) 6jRF[N8
{ 7>wSbAR<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;,JCA# N
//Utility.log(in.readLine()); 53=s'DZ
sHeader=httpConnection.getHeaderFieldKey(i); t 4{{5U'\
if(sHeader!=null) @/`b:sv&*
{ d.% Vm&3
if(sHeader.equals("Content-Length")) fwf]1@#
{ OY51~#BF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LC*@/((
break; u(\b1h n
} )e4nKh],
} D/9&pRsO
else |mc!v*O
break; i=o<\{iV:
} tlCgW)<?
} xx#;)]WT
catch(IOException e){e.printStackTrace ();} g(,gg1mG
catch(Exception e){e.printStackTrace ();} gK9@-e
55zimv&DV
iU~oPp[e
Utility.log(nFileLength); 0KHA5dt
.?<,J
kZ[E493bV
return nFileLength; 7$\;G82_
} S$=])^dur
cmZ39pjBJ
A>bo Xcr
//保存下载信息（文件指针位置） Qg%B<3 <
private void write_nPos() n*9)Y~
{ b_|`jHes
try{ <I&X[Sqp
output = new DataOutputStream(new FileOutputStream(tmpFile)); t1 OnA#]/_
output.writeInt(nStartPos.length); 54-sb~]
for(int i=0;i<nStartPos.length;i++) SYw>P1
{ K!).QB'
// output.writeLong(nPos); "/S-+Ufn
output.writeLong(fileSplitterFetch.nStartPos); }{n[_:[7
output.writeLong(fileSplitterFetch.nEndPos); dK#:io[Nz
} nkG1&wiX
output.close(); Elom_
} lOCMKaCD
catch(IOException e){e.printStackTrace ();} ^I5k+cL
catch(Exception e){e.printStackTrace ();} MQG(n+c
} qdx(wGG
G yvEc3|@
o3#qp>R
//读取保存的下载信息（文件指针位置） Xat>d>nJ]
private void read_nPos() *_}ft-*w
{ h rW
try{ ey_3ah3x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5*/~) wN\U
int nCount = input.readInt(); dAh&Z:86\
nStartPos = new long[nCount]; [1F.
nEndPos = new long[nCount]; H!y1&
for(int i=0;i<nStartPos.length;i++) `+CRUdr
{ `WboM\u
nStartPos = input.readLong(); yTm/P!1S
nEndPos = input.readLong(); ]o$aGrZ
} %c<e`P;
input.close(); V`fp%7W
} xA& tVQ2!
catch(IOException e){e.printStackTrace ();} 8d?r )/~
catch(Exception e){e.printStackTrace ();} i+ ]3J/J
} ZP &q7HK\
x"9`w42\r
X4_1kY;
private void processErrorCode(int nErrorCode) pZ,=iqr
{ n`8BE9h^
System.err.println("Error Code : " + nErrorCode); 2F%2K?$`Ej
} CBN,~wzP*
fd!bs*\X
++w7jVi9
//停止文件下载 R.@I}>
public void siteStop() XD%@Y~>+
{ t1}R#NB
bStop = true; OyH>N/
for(int i=0;i<nStartPos.length;i++) "yJFb=Xdq
fileSplitterFetch.splitterStop(); f^Sl(^f
o-a\T
aO)Cq5
} (yA`h@@WS
} U2<8U
//负责部分文件的抓取 4zKmoYt
**FileSplitterFetch.java 3V=wW{;x
*/ kn<IWW_t
package NetFox; KG<. s<
~8:q-m_h
2>TOCBB"
import java.io.*; Oxsx\f_
import java.net.*; =\~<##sRJ
~/^q>z!\4
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public class FileSplitterFetch extends Thread { /M!b3bmA
g?B4b7II
8uAA6h+
String sURL; //File URL H j [!F%
long nStartPos; //File Snippet Start Position Rtpk_ND!
long nEndPos; //File Snippet End Position j/ [V<
int nThreadID; //Thread's ID <ks+JkW_
boolean bDownOver = false; //Downing is over 2(I S*idq
boolean bStop = false; //Stop identical gZq_BY_U
FileAccessI fileAccessI = null; //File Access interface 41uiW,
tVQq,_9C
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XM1; >#kz
{ \MqOHM.[
this.sURL = sURL; ;P *`v
this.nStartPos = nStart; %\"<lyD
this.nEndPos = nEnd; !E7JDk''@
nThreadID = id; mqj]=Fq*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cl04fqX
} ci 4K Nv;
9]C%2!Ur,
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public void run() Oh# z zo
{ `6y=ky.,
while(nStartPos < nEndPos && !bStop) dJv2tVm&'
{ ] M`%@ps
[s4|+
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try{ )Cu2xRr^`
URL url = new URL(sURL); }#r awVe=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @yM$Et5
httpConnection.setRequestProperty("User-Agent","NetFox"); XEegUTs
String sProperty = "bytes="+nStartPos+"-"; Z_U4Yy'NNw
httpConnection.setRequestProperty("RANGE",sProperty); j)ME%17
Utility.log(sProperty); }1 ,\*)5
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po\(O8#5U
InputStream input = httpConnection.getInputStream(); }7*|s+F(f
//logResponseHead(httpConnection); 7Q^p|;~a
hCBre5
iC{(vL0P+
byte[] b = new byte[1024]; KFgq3snH
int nRead; OUq%d8W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GQ(*k)'a
{ e@Mg9VwDc
nStartPos += fileAccessI.write(b,0,nRead); O^J=19Ri
//if(nThreadID == 1) gky+.EP.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4VF4 8
} +T\<oj%}2
Mz6\T'rC
a,36FF~&
Utility.log("Thread " + nThreadID + " is over!"); x<h|$$4S
bDownOver = true; V0NLwl O
//nPos = fileAccessI.write (b,0,nRead); C$p012D1
} ebn3r:IU-
catch(Exception e){e.printStackTrace ();} $K.DLqDt
} + -uQ] ^n
} f&j\gYWq
B(WmJ6e
up{0ehr
//打印回应的头信息 3[j,d]\|
public void logResponseHead(HttpURLConnection con) ?q7MbQw
{ Zs(BViTb|
for(int i=1;;i++) AyWdJ<OU
{ eR4ib-nS
String header=con.getHeaderFieldKey(i); R?zlZS.~
if(header!=null) -oUGmV_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x <a}*8"
Utility.log(header+" : "+con.getHeaderField(header)); 8 :WN@
else )RN3Oz@H
break; [n2zdiiBd
} Zb=;\l*&
} ;vneeW4|
gg.]\#3g
)!kt9lK
public void splitterStop() \pk9i+t
{ S{?l/*Il*_
bStop = true; qdLzB
} je@&|9h
>yr;Y4y7K
e]nP7TIU
} )H@<A93
"n]x%. *
)u+O~Y95&i
/* CuK>1_Dq
**FileAccess.java bfpeK>T
*//文件访问(定位，写) :1Nc6G
package NetFox; 4evNZ Q
import java.io.*; e,{k!BXU#'
6/#+#T
{ TI,|'>5[
public class FileAccessI implements Serializable{ i3mw.`7
KB^8Z@(+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OwEV$Q
RandomAccessFile oSavedFile; !yT=*Cj4
long nPos; _p0gXb1m`
f,i2U|1pbj
x]yIe&*('
public FileAccessI() throws IOException [Rub
{ Op8Gj `
this("",0); Uj\t04
} }cI-]|)|2
x${C[gxq9F
h^_^)P+;
public FileAccessI(String sName,long nPos) throws IOException 34X]b[^
{ MM]0}65KG
oSavedFile = new RandomAccessFile(sName,"rw"); %TRJ
this.nPos = nPos; cWyf04-?
oSavedFile.seek(nPos); #'O9Hn({
} P=1Ku|k
?*$uj(
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public synchronized int write(byte[] b,int nStart,int nLen) 5x|$q kI
{ |EdEV*.ej
int n = -1; &>+5 8
try{ g33Y$Xdk
oSavedFile.write(b,nStart,nLen); J/D~]U
n = nLen; Du +_dr^4
} U\,N
catch(IOException e) ?$ov9U_
{ lK/4"&
e.printStackTrace (); ^7ID |uMr
} *~4<CP+"0
O-ENFA~E;v
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return n; a * CXg.i
} FeS ,TQ4j
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} a!4p$pR
y{<js!au
Vt \g9-[
/* fj['M6+wd
**SiteInfoBean.java sr[[xzL
*/ sw}^@0ua=
package NetFox; x4>"m(&%
-K$ugDi
BMQ4i&kF|
public class SiteInfoBean { !gV{[j?~zr
OGLA1}k4
82+2PE{
private String sSiteURL; //Site's URL **z^aH?B2
private String sFilePath; //Saved File's Path =`>ei
private String sFileName; //Saved File's Name },}g](!m
private int nSplitter; //Count of Splited Downloading File 3!cenyE
/&G|.Cx
Het>G{
public SiteInfoBean() 6C"zBJcGc
{//nSplitter的缺省值为5 k:iy()n[
//default value of nSplitter is 5 W5Jy"]^I
this("","","",5); ~iiDy;"
} \(=xc2
-R1;(n)
9ghUiBPiL:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +t*I{X(
{ YMNLn9
sSiteURL= sURL; X{i>Q_8>
sFilePath = sPath; .waj.9&[l
sFileName = sName; =d<~:!)
this.nSplitter = nSpiltter; +_vf=d
#H |p)2k
ek/zQM@%
} FYu30
0*kS\R=P
XV4aR3n{Q
public String getSSiteURL() ?li/mc.XG
{ FqGMHM\J
return sSiteURL; Y%y
} 0t"Iq71/
~,)D n
Y=_*Ai
public void setSSiteURL(String value) l O*
{ [4bE"u
sSiteURL = value; &Qj1uf92.
} ?dv-`)S&
Wlq3r#
/zQx}U)TP
public String getSFilePath() [h&s<<# D
{ v+trHdSBYE
return sFilePath; vF~q".imC
} P|lDW|}D@
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]B~(yh
public void setSFilePath(String value) 73]t5=D:
{ }hm_Ws
sFilePath = value; m J$[X
} #)48dW!n
o@[o6.B<
@;y@Hf'Jv
public String getSFileName() (~5]1S}F
{ =b1 y*?
return sFileName; `)KGajB
} m#O; 1/P
m]Qs BK
PQYJnx}
public void setSFileName(String value) #uC}IX2n
{ |f1^&97=+
sFileName = value; ^'Rs`e
} SfrM|o
z?kE((Ey
pEN`6*
public int getNSplitter() }vgM$o
{ M%Vp_ 0
return nSplitter; hPGDN\#LD
} >dw 0@T&p
=`N0
=,qY\@fq
public void setNSplitter(int nCount) lZ2gCZ
{ 0(Z:QqpU$
nSplitter = nCount; cG@Wo8+
} \LQZoD?W
} tux`-F
#SI]^T|
k.)YFKi
/* 2S[:mnK
**Utility.java M_cm,|FF
*/ Hv:~)h$
package NetFox; W>&*.3{v
u%1JdEWZd
|DVFi2
public class Utility { 87)/dHc
At[SkG}b
\)aFYDq#\
public Utility() X2,v'`U5&
{ cf"!U+x
j!;E>`g
ZdPqU\G^q
} pj3H4yCM:
yw7bIcs|#b
//线程睡眠 gF293Ez
public static void sleep(int nSecond) %=s2>vv9
{ SymlirL
try{ Wap\J7NY
Thread.sleep(nSecond); B(eiRr3
} !Zc#E,
catch(Exception e) ^)|tf\4
{ Dd, &a
e.printStackTrace (); mT|r:Yr:
} el<[Ng[
} qM3(OvCt
!kh:zTP
//日志 z`u$C+Ov
public static void log(String sMsg) u'T>Y1I
{ ku>Bxau4>
System.err.println(sMsg); X%;4G^%ZI
} vYo~36
Ar_Yl|a
SF ^$p$mC
public static void log(int sMsg) Pe11azJ
{ 3fYfj
System.err.println(sMsg); 5;XU6Rz!
} N?A}WW#
} q!h'rX=_-
N!\1O,
!<X/_+G\
/* lX50JJwk
**TestMethod.java !SLfAFcS
*/ 2J3y 1
package NetFox; DD>n-8M@>
Gsm.a
!9V; 8g
public class TestMethod { /7.//klN
2@N-#x'
z'gJy
public TestMethod() HA&hu/mw_
{ ///xx/weblogic60b2_win.exe 9El{>&Fs4
try{ :#N]s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jF#Dc[*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N~?#Qh|ZnU
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;1r|Bx<5
fileFetch.start(); yhnPS4DC
} $g,v]MW
catch(Exception e){e.printStackTrace ();} W}Rzn
52'6wwv6?
UzV78^:,iD
} DTdqwe6pi
diKl}V#u
n6c+Okj
public static void main(String[] args) _@_EQ!=
{ eZg>]<L
new TestMethod(); gmiLjI
} 7eFFKl
} x-q_sZ^8
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