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)); AEd]nVV Q
} ?RQ_LA;
for(int i=0;i<nEndPos.length-1;i++) |5TzRz
{ NpLZ ,|H
nEndPos = nStartPos[i+1]; G nPrwDB
} m"/ o4
nEndPos[nEndPos.length-1] = nFileLength; L.?QZN%cN
} ;V0^uB.z
} W"n0x8~sV
K 7OIT2-
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//启动子线程 urhOvC$a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A@<a')#>)
for(int i=0;i<nStartPos.length;i++) ? FlQ\q
{ S7 !;Z@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NH'Dz6K5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zvbO q
nStartPos,nEndPos,i); bYUG4+rD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H@!]5 <:9
fileSplitterFetch.start(); 6^e}^~|
} r#'ug^^k$X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %zz,qs)Eu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x/dyb.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eXQLE]L]
nEndPos = " + nFileLength); |i\%>Y,
// fileSplitterFetch[nPos.length-1].start(); BIh^b?:zU
Mz6PH)e;
`Kbf]"4q
//等待子线程结束 Jo''yrJpB
//int count = 0; Ji4JP0
//是否结束while循环 8I[=iU7]l
boolean breakWhile = false; Ef$a&*)PH
FDal;T
Ggk#>O G
while(!bStop) `0, G'F
{ t>!Ok
write_nPos(); 46##(4RF
Utility.sleep(500); tj4/x7!
breakWhile = true; 3O*^[$vM
&u2H^ j
C2{*m{ D
for(int i=0;i<nStartPos.length;i++) T5Iz{Ha
{ p1UYkmx[
if(!fileSplitterFetch.bDownOver) UvR.?js(O
{ sBk|KG
breakWhile = false; 7!dj&?
break; m6uFmU*<M}
} *#9?9SYSk
} [Ob09#B%:5
if(breakWhile) Ggry,3X3
break; =P%?{7
;pj,U!{%s\
-}u1ZEND
//count++; " GY3sam
//if(count>4) !bs5w_@
// siteStop(); mw&'@M_(7
} {T-=&%||
x[=,$;o+
3Cgv($xl&
System.err.println("文件下载结束！"); "5204I
} -tIye{
catch(Exception e){e.printStackTrace ();} iPdS>ee
} lAR1gHhJ
Kr?<7vMT5
~BiLzT1,
//获得文件长度 Gz52^O:
public long getFileSize() iG#92e4
{ ,FwpHs $A
int nFileLength = -1; (8baa.ge
try{ #(QS5J&Qq
URL url = new URL(siteInfoBean.getSSiteURL()); +Sc2'z>R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NL,6<ZOon,
httpConnection.setRequestProperty("User-Agent","NetFox"); _Q'f^Kj
0avtfQ +f
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int responseCode=httpConnection.getResponseCode(); 10Q!-K),p
if(responseCode>=400) IrUoAQ2xpG
{ V?)YQB
processErrorCode(responseCode); eX1_=?$1P
return -2; //-2 represent access is error +|Izjx]ZV
} `A9fanh
*{,}pK2*
X.sOZb?$
String sHeader; Z;S)GUG^
eLLOE)x
;l^'g}dQ^
for(int i=1;;i++) 4V c``Um
{ O`$\Plt|v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +koW3>
//Utility.log(in.readLine()); >{l b|Vx
sHeader=httpConnection.getHeaderFieldKey(i); KrR`A(=WL
if(sHeader!=null) LP !d|X
{ -(7oFOtg
if(sHeader.equals("Content-Length")) m%'T90mi
{ :|8!w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Apj[z2nr
break; [nG[ x|;|
} ?9%$g?3Z
} TqSjL{l%
else X#Ob^E%J
break; Qsw.429t
} VCVKh
} \TYVAt] ?
catch(IOException e){e.printStackTrace ();} 6J_$dzw
catch(Exception e){e.printStackTrace ();} I2krxLPd
0dQ\Y]b
Z?d][zGw
Utility.log(nFileLength); c[T@lz(!
cltx(C>
qA[cF$CIl)
return nFileLength; EG|_YW7
} Q+/P>5O/
x0%yz+i{:
$d,/(*Y#-
//保存下载信息（文件指针位置） pFV~1W:
private void write_nPos() uH(M@7"6_!
{ |Qb@.
try{ xj9xUun
output = new DataOutputStream(new FileOutputStream(tmpFile)); *K& $9fah
output.writeInt(nStartPos.length); F(ZczwvR
for(int i=0;i<nStartPos.length;i++) >^IUS8v
{ OG_v[ C5
// output.writeLong(nPos); y2mSPLw
output.writeLong(fileSplitterFetch.nStartPos); F>5b[q6~4
output.writeLong(fileSplitterFetch.nEndPos); g[HuIn/
} ^go3F{;4i
output.close(); oad /xbp@/
} $e{[fmx
catch(IOException e){e.printStackTrace ();} 7G7"Zule*j
catch(Exception e){e.printStackTrace ();} pe>?m^gz[
} Jw>na _FJ
2kk; z0f
A`Rs n\
//读取保存的下载信息（文件指针位置） F\v~2/J5v
private void read_nPos() So75h*e
{ R,BINp
try{ h(GSM'v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,b5vnW\
int nCount = input.readInt(); 6'x3g2C/
nStartPos = new long[nCount]; g3yZi7b5FU
nEndPos = new long[nCount]; Gm3`/!r
for(int i=0;i<nStartPos.length;i++) B#}EYY
{ mxu!$wx
nStartPos = input.readLong(); uHRxV"@}[1
nEndPos = input.readLong(); "c?31$6
} xn@oNKD0
input.close(); g>#}(u!PH
} | +uc;[`
catch(IOException e){e.printStackTrace ();} th<>%e}5c
catch(Exception e){e.printStackTrace ();} Oqt{ uTI~
} d(@ ov^e-
yW\kmv.O
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private void processErrorCode(int nErrorCode) 1~},}S]id
{ fU\;\
System.err.println("Error Code : " + nErrorCode); ori[[~OyB
} FQE(qltf,
cct/mX2&~
.6I'V3:Kg
//停止文件下载 :h/v"2uDN
public void siteStop() eAqpP>9n
{ hy@b/Y![M
bStop = true; M;NIcM
for(int i=0;i<nStartPos.length;i++) s?&S<k-=fr
fileSplitterFetch.splitterStop(); Xy`'h5
R3LIN-g(
:zvAlt'q=
} ^<uQ9p^B
} V]"pM]>3X
//负责部分文件的抓取 Z}Q/u^Z
**FileSplitterFetch.java a;nYR5f
*/ WS?Y8~+{5
package NetFox; ?AQA>D#W
;Bw3@c
^R)]_
import java.io.*; 2$VSH&
import java.net.*; feeHXKD|
1'iQlnMO@
g6S-vSX,
public class FileSplitterFetch extends Thread { }RYPr
-}( o+!nl
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String sURL; //File URL "3|OB, <;:
long nStartPos; //File Snippet Start Position M'oZK
long nEndPos; //File Snippet End Position NS TO\36
int nThreadID; //Thread's ID AxF$7J(
boolean bDownOver = false; //Downing is over oIMS >&
boolean bStop = false; //Stop identical 1mR@Bh
FileAccessI fileAccessI = null; //File Access interface 52,'8` ]
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Y=O-^fL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1CM8P3
{ )q\6pO@
this.sURL = sURL; KoWG:~>|
this.nStartPos = nStart; #`l&HV
this.nEndPos = nEnd; I3izLi
nThreadID = id; +"JWsD(C(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :f7vGO"t
} iP:^nt?
_JA)""l%
+_gA"I
public void run() gS`Z>+V5!c
{ G `B=:s]
while(nStartPos < nEndPos && !bStop) cWo__EE
{ Y?zo")
<Lt"e8Z>x
rSm#/)4A
try{ gQ%mVJB{(
URL url = new URL(sURL); 8DbP$Wwi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o]&P0 b
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Z"N2D)."
String sProperty = "bytes="+nStartPos+"-"; a1[J>
httpConnection.setRequestProperty("RANGE",sProperty); `0w!&
Utility.log(sProperty); BQeg-M
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'aEN(Mdz1e
InputStream input = httpConnection.getInputStream(); \_i22/Et
//logResponseHead(httpConnection); BO6XY90(
e 0Z2B2
D~`RLPMk
byte[] b = new byte[1024]; S&k/Pc
int nRead; 0AoWw-H6V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MBU4Awj
{ No+BS%F5
nStartPos += fileAccessI.write(b,0,nRead); dldS7Q
//if(nThreadID == 1) nLPd]%78>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 322-'S3<
} w vI v+Q9
ed3wj3@
%\)AT"
Utility.log("Thread " + nThreadID + " is over!"); }g|9P SbJ
bDownOver = true; / T_v8{D
//nPos = fileAccessI.write (b,0,nRead); O`N,aYo
} EaH/Gg3
catch(Exception e){e.printStackTrace ();} [D?d~pB
} /rK/l
} g0s4ZI+T
wqap~X
S@~ReRew2
//打印回应的头信息 f}ch1u>
public void logResponseHead(HttpURLConnection con) fjuPGg~
{ *#@{&Q(Qh
for(int i=1;;i++) ,:V[H8 ?
{ #T`1Z"h<
String header=con.getHeaderFieldKey(i); _G/uDP%
if(header!=null) +@7c:CAy(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B)0;gWK
Utility.log(header+" : "+con.getHeaderField(header)); ,W/Y@ScC
else |S]fs9
break; 73{<;z}i
} b.}J'?yLm
} Eq=JmO'gHs
Bi"cWO
e ^`La*n
public void splitterStop() 8vfC
{ }>3jHWxLc
bStop = true; at2)%V)
} ?nE9@G5Gc
_(8N*q*w
RmOkb~
} uBC#4cX`D*
1Vz3N/AP%?
{?A/1q4rr
/* 8)83j6VF
**FileAccess.java /;u=#qu(E-
*//文件访问(定位，写) ')2LP;(
package NetFox; q%)."10}]
import java.io.*; ltkA7dUbu
e<~bDFH
%/!f^PIwX
public class FileAccessI implements Serializable{ 9OlJC[
?/~Q9My
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8k.#4}fP
RandomAccessFile oSavedFile; "tDB[?
long nPos; r $YEq5
)2u_[Jc=
UjyrmQf
public FileAccessI() throws IOException 9PaV*S(\TR
{ , 0?_? GO
this("",0); ]IDhE{
} V~Jt
Tq6\oIBkV
e#WASHZN
public FileAccessI(String sName,long nPos) throws IOException OL@$RTh
{ {"rL3Lk
oSavedFile = new RandomAccessFile(sName,"rw"); @f,/K1k
this.nPos = nPos; )U8=-_m
oSavedFile.seek(nPos); ZK<c(,oZ^
} 5 (q4o`
ogV v 8Xb
|F qujZz
public synchronized int write(byte[] b,int nStart,int nLen) ?dk)2
{ |ss4pN0X
int n = -1; [EQTrr( D
try{ rV*Ri~Vx
oSavedFile.write(b,nStart,nLen); `?d` #)Ck
n = nLen; ?-<>he
} SF"r</c[
catch(IOException e) R#rfnP >
{ 5E}]U,$
e.printStackTrace (); bJynUZ
} DD[<J:6
I-Am9\
w.+G+r=
return n; ~{{7y]3M-
} S&Hgr_/}c
gTdr
h66mzV:`
} _d>{Hz2
n9Vr*RKM)
`y{[e j
/* `@So6%3Y|
**SiteInfoBean.java /7ykmW
*/ z.tN<P7
package NetFox; ke2M&TV
UunZ/A$]m
w,0OO f
public class SiteInfoBean { V~$?]Z%_
tK6=F63e
:g+wv}z
private String sSiteURL; //Site's URL MaF4lFmS
private String sFilePath; //Saved File's Path CWb*bw0
private String sFileName; //Saved File's Name /HdjPxH
private int nSplitter; //Count of Splited Downloading File ^#4<~zU
on1B~?*D
*{O[}
public SiteInfoBean() :+8qtIytKX
{//nSplitter的缺省值为5 {?r5~T`2
//default value of nSplitter is 5 Sj viH
this("","","",5); e`K{
} +{%)}?F
6yC4rX!a
\]3[Xw-$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lx|0G $
{ .F/s(
sSiteURL= sURL; %kP=VUXj
sFilePath = sPath; F><ficT
sFileName = sName; CbOCL~ "
this.nSplitter = nSpiltter; Ian+0 ?`e
yIWgC[
w/9%C(w6
} K.b:ae^k
8KsPAK_
NC sem
public String getSSiteURL() #1WCSLvtV
{ Q9&H/]"v
return sSiteURL; fGWXUJ
} ~{pds
"kjSg7m*:
l]~IZTC
public void setSSiteURL(String value) }q,dJE
{ z:&/O&?
sSiteURL = value; xrv0%
} fT YlIT9
hUEA)c
Mt@Ma ]!
public String getSFilePath() WYIv&h<h"
{ +fQJ#?N2n
return sFilePath; dZ4c!3'F
} Q 87'zf
T9Fe!yVA
,}NTV~
public void setSFilePath(String value) -wh
{ Zg|l:^E
sFilePath = value; DHZ`y[&}|N
} x~](d8*=
F 1l8jB\
W>'(MB$3
public String getSFileName() QZuKM'D+
{ h05<1>?|
return sFileName; 20I/En
} e`Co ='
Of}C.N8
?P/73p
public void setSFileName(String value) 7R5+Q\W
{ 1\g r ;b
sFileName = value; 5<P6PHdY
} *U`R<mV\
AS'+p%(
8isQL
public int getNSplitter() bCiyz+VyJn
{ yet~
return nSplitter; yD@1H(yM
} 69`*u<{PC
)"7z'ar
d\25
public void setNSplitter(int nCount) l(\F2_,2W
{ ?-tNRIPW@p
nSplitter = nCount; D ,[yx='
} /QQjb4S}
} [X*u`J
bD-OEB
B>@l(e)b
/* k$>5v +r0
**Utility.java qd<I;*WV
*/ `Jh<8~1
package NetFox; _(I)C`8m
L~RFI&b
c0;rvw7
public class Utility { ^F&j;8U
z[y
v8n^~=SH
public Utility() amQTPNI
{ n~0MhE0H
}_('3C,Ba
&(e5*Q
} cwzgIm+
C>SOd]
//线程睡眠 ^'fgQyj
public static void sleep(int nSecond) A6 `a
{ Y?L>KiM$
try{ {|B[[W\TN
Thread.sleep(nSecond); O0$V+fE
} T\bpeky~
catch(Exception e) 2'-84
{ |sEuhP\A3
e.printStackTrace (); F!p;]B
} cDK)zD
} Vhr6bu]
UcH#J &r
//日志 N(2M w:}
public static void log(String sMsg) ]&dPY[~,/i
{ ;>S|?M4GZ
System.err.println(sMsg); Q7i(M >|O
} be$']}cP
9A/bA|$
&I%E8E
public static void log(int sMsg) *LuRo
{ 4C;y2`C
System.err.println(sMsg); 9,JWi{lIv
} Et0)6^-v
} +L@\/=;G
L27WDm^)
) .KMZ]
/* `zB bB^\`W
**TestMethod.java /)kx`G_
*/ PB!XApTb
package NetFox; y,bDi9*|
vVrM[0*c
{m@tt{%
public class TestMethod { o8v,178
dCo3VF"u
Dwr 9}Z-]
public TestMethod() 3s67)n
{ ///xx/weblogic60b2_win.exe <]X6%LX
try{ +S`cUn7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L./c#b!{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g-1j#V`5
SiteFileFetch fileFetch = new SiteFileFetch(bean); X$6QQnyR
fileFetch.start(); [J(b"c6
} cbs ;
catch(Exception e){e.printStackTrace ();} adAdX;@e`
$RNHRA.
+\)Y,@cw
} vU]n0)<KB
@LSh=o+
u[oV Jvc
public static void main(String[] args) #dD0vYT&od
{ ~*9Ue@
new TestMethod(); hJD3G |E
} o)]O
} 3^xq+{\)
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