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)); G$1gk^G's
} 5](,N^u{):
for(int i=0;i<nEndPos.length-1;i++) #Kt5+"+7
{ =po5Q6@i
nEndPos = nStartPos[i+1]; +?+iVLr!l}
} pXf5/u8&
nEndPos[nEndPos.length-1] = nFileLength; S<>u
} @pV&{Vp
} Q#}c5TjVr
$}.#0c8I
' eH Fa
//启动子线程 w"OeS;#e:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *wV`7\@
for(int i=0;i<nStartPos.length;i++) %$=}ePD
{ m-'+)lB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 02q*z>:^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fX}dQN~z
nStartPos,nEndPos,i); !==C@cH<N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zqm/<]A*l
fileSplitterFetch.start(); ;c|G
} 4n/CSAT1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <v$yXA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :2-!bLo}&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M][Zu[\*
nEndPos = " + nFileLength); /igbn
// fileSplitterFetch[nPos.length-1].start(); A#CGD0T
xcC^9BAj
7jYW3
//等待子线程结束 HfA@tZ5q|U
//int count = 0; U_AmRiy
//是否结束while循环 :{x
boolean breakWhile = false; MXynv";<H
i~.9B7hdE
hA387?
while(!bStop) Jl{g"N{2u'
{ qWw{c&{Q],
write_nPos(); O],]\M{GL
Utility.sleep(500); 7-[^0qS
breakWhile = true; #&&
;"+]bne~
rB.LG'GG]
for(int i=0;i<nStartPos.length;i++) W(jP??up
{ eG%Q 3h
if(!fileSplitterFetch.bDownOver) e*pYlm
{ RhI>Ak;-
breakWhile = false; dwmZ_m.
break; |"k+j_/+
} o'!WW
} 5+Hw @CY3
if(breakWhile) Tw!_=zy(Gw
break; )X5en=[)O
Schvwlm~i
7=pJ)4;ZA
//count++; +t<'{KZ7;
//if(count>4) Hb@PQcj
// siteStop(); ,Cj` 0v#
} R;F z"J
)r6d3-p1
);*#s~R
System.err.println("文件下载结束！"); P: )YKro]
} 3L-}B#tI
catch(Exception e){e.printStackTrace ();} 0 A6%!h
} 7A4_b8
Nx<%'-9)|
z#t;n
//获得文件长度 5hE mXZ%
public long getFileSize() fz`\-"f]
{ U-lN-/=l6
int nFileLength = -1; h|XLL|:
try{ 5)<}a&;{
URL url = new URL(siteInfoBean.getSSiteURL()); :DR}lOi`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p|VgtQ/)%
httpConnection.setRequestProperty("User-Agent","NetFox"); 4'U #<8
Wf5ohXm>
m7NrS?7
int responseCode=httpConnection.getResponseCode(); p^?]xD(
if(responseCode>=400) jt4c*0z
{ <hmRr
processErrorCode(responseCode); KcF#c_f
return -2; //-2 represent access is error =Vi>?fWpn=
} AJR`ohh
cj9<!"6
FdMxw*}
String sHeader; )L%[(iI,x
1bpjj'2%x
Ah1fcXED
for(int i=1;;i++) i")ucrf
{ 3NxwQ,~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +G[N lb
//Utility.log(in.readLine()); t.= 1<Ed
sHeader=httpConnection.getHeaderFieldKey(i); 88M$mjx
if(sHeader!=null) 6@cT;=W;xj
{ Zh3hCxXa
if(sHeader.equals("Content-Length")) }pL#C
{ a^.5cJ$]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f)%8*B
break; _Sn7z?
} br_D Orq|
} G5'HrV
else yfCdK-9+B
break; A"R5Fd%6pc
} Q:sw*7"F
} Qr$Ay3#k
catch(IOException e){e.printStackTrace ();} \KT}T
catch(Exception e){e.printStackTrace ();} 9ld'SB:#
*/E5<DO
=U_O;NC
Utility.log(nFileLength); }='1<~0
<ZgbmRY8
M3/_E7Qoj
return nFileLength; gDBdaxR<
} 9M!J7 W
,pMH`
n0<I
//保存下载信息（文件指针位置） ]Z#=w
private void write_nPos() 9|9Hk1
{ k\`~v$R3
try{ nK;c@!~pS
output = new DataOutputStream(new FileOutputStream(tmpFile)); sqP (1|9
output.writeInt(nStartPos.length); \oc*
for(int i=0;i<nStartPos.length;i++) #JIh-h@
{ "0#d F:qt
// output.writeLong(nPos); 6 s1lf!
output.writeLong(fileSplitterFetch.nStartPos); +4*jO5EZ
output.writeLong(fileSplitterFetch.nEndPos); 'Z=8no`<
} AQa;D2B$
output.close(); pQf5s7
} "~^#{q
catch(IOException e){e.printStackTrace ();} A6#5 z
catch(Exception e){e.printStackTrace ();} gS$?#!f
} fkmN?CU{1%
v"N%w1`.e
MeXGE
//读取保存的下载信息（文件指针位置） F;;\I
private void read_nPos() jizp\%W+
{ `X ;2lgL
try{ POtwT">z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xgV(0H}Mf
int nCount = input.readInt(); J52- qR/
nStartPos = new long[nCount]; hxQx$
nEndPos = new long[nCount]; 2J5RZg9jL
for(int i=0;i<nStartPos.length;i++) Wz]ny3K[.
{ {,`)
nStartPos = input.readLong(); ^a+H`RD
nEndPos = input.readLong(); zv}3Sl@
} aS,M=uqqK
input.close(); qkk!1W
} _bm8m4Lk
catch(IOException e){e.printStackTrace ();} EmO{lCENk
catch(Exception e){e.printStackTrace ();} mM6X0aM
} 'ZboLoS*-
B(TE?[ #
s}5,<|DL
private void processErrorCode(int nErrorCode) CV )v6f
{ VA^yv1We
System.err.println("Error Code : " + nErrorCode); [9U::
} 0V_dg |.
6mAaFDI,R
+P5\N,,7R
//停止文件下载 %SHgXd#X
public void siteStop() v62M8r,Y
{ dNg5#?mzT5
bStop = true; ap y#8]
for(int i=0;i<nStartPos.length;i++) XD=p:Ezh
fileSplitterFetch.splitterStop(); Ns}BE H
WY)*3?
] eO25,6
} Dq:>]4%
} y/(60H,{{
//负责部分文件的抓取 ;VI/iwg
**FileSplitterFetch.java mufJ@YS#
*/ `: R7jf
package NetFox; 7I0[Ii
Z>t,B%v
)EhRqX9
import java.io.*; P^Tk4_,0
import java.net.*; j{?ogFfi
vl,Ff9
3{*nG'@Mal
public class FileSplitterFetch extends Thread { Q eZg l!
S_ELV#X
JsZLBq*lP
String sURL; //File URL 9\J.AAk~/
long nStartPos; //File Snippet Start Position <<5x"W(,
long nEndPos; //File Snippet End Position LI`H,2Km
int nThreadID; //Thread's ID [')C]YQb=
boolean bDownOver = false; //Downing is over ,N`cH\
boolean bStop = false; //Stop identical e*?@6E
FileAccessI fileAccessI = null; //File Access interface )GC9%mF;
_a`J>~$
_d`)N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &u}]3E'-k
{ :*6#(MX
this.sURL = sURL; ,u&K(Z%
this.nStartPos = nStart; |Y")$pjz
this.nEndPos = nEnd; W8><
nThreadID = id; 6PyODW;R/5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P1>?crw
} &4R-5i2a
]QJWqY
![l`@NH[U
public void run() 2C59fXfd
{ vkgAI<
while(nStartPos < nEndPos && !bStop) WPpS?
{ dtDT^~
zHu w[
\zMx~-2oN
try{ pX LXkF?
URL url = new URL(sURL); |[B JZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8uD%
httpConnection.setRequestProperty("User-Agent","NetFox"); |iLf;8_:
String sProperty = "bytes="+nStartPos+"-"; Rxfhk,I
httpConnection.setRequestProperty("RANGE",sProperty); .FWi$B';
Utility.log(sProperty); 5%K(tRc|
ucwUeRw,
JMVh\($,x
InputStream input = httpConnection.getInputStream(); Sz'H{?"
//logResponseHead(httpConnection); )ld`2) 4
1[k.apn
*MM8\p_PuT
byte[] b = new byte[1024]; OS]FGD3a
int nRead; N6thbH@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z1vSt[s
{ nSR<(-j!
nStartPos += fileAccessI.write(b,0,nRead); 59X'-fg,
//if(nThreadID == 1) ! a!^'2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .;,` bH0
} %SKJ#b
9tBE=L=
CjT]!D)s
Utility.log("Thread " + nThreadID + " is over!"); 3^-yw`
bDownOver = true; RJa1pYK
//nPos = fileAccessI.write (b,0,nRead); I\WBPI
} WN6%%*w
catch(Exception e){e.printStackTrace ();} |:b!e
} >uy(N
} K^f&+`v6_
]rMHO
2}xvM"k=k
//打印回应的头信息 $dkkgsw7
public void logResponseHead(HttpURLConnection con) *h)|Ks
{ v~`'!N8
for(int i=1;;i++) ,%4~ulKMn
{ =Yt)b/0b9
String header=con.getHeaderFieldKey(i); O&@pi-=o
if(header!=null) "^&Te%x_b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;oGpB#[zO
Utility.log(header+" : "+con.getHeaderField(header)); ''3b[<
else 9~ rYLR(v
break; }Jm~b9j
} gBd@4{y6C.
} \@F~4,VT
7I;A5f
ka?EXF:
public void splitterStop() E;-*LT&{
{ k@Mt8Ln
bStop = true; y@2$sK3K
} [iGL~RiXtn
07#e{
mr<camL5
} sMNhD/bb
+LB2V3UZ
WNcJ710k27
/* e763yd
**FileAccess.java 45U!\mG
*//文件访问(定位，写) UtYwG#/w
package NetFox; $c1xh.
import java.io.*; qi=v}bp&
)Nnrsa
(K`@OwD
public class FileAccessI implements Serializable{ |$G|M=*LN
qj:\)#I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1^AG/w
RandomAccessFile oSavedFile; <Oihwr@5<
long nPos; Mi:i1i cdn
),5|Ves;t[
v0u, :eZ4
public FileAccessI() throws IOException 91\]Dg
{ v]c+|nRs
this("",0); a2SXg A
} mJ JF
BI:O?!:9)
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public FileAccessI(String sName,long nPos) throws IOException xV>sc;PEb
{ n#"N"6s
oSavedFile = new RandomAccessFile(sName,"rw"); ,?(U4pzX
this.nPos = nPos; 9?zi
oSavedFile.seek(nPos); /j"aOLL|
} bTc^huP
0P^&{ek+)
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public synchronized int write(byte[] b,int nStart,int nLen) z6uHe{|
{ *yqke<o9)
int n = -1; Mt\.?V:
try{ G0b##-.'^
oSavedFile.write(b,nStart,nLen); /amWf^z
n = nLen; fir#5,*q|
} Q=h37]U+
catch(IOException e) Wp(Rw4j
{ a Juv{
e.printStackTrace (); @j'GcN vs
} X6so)1jJ
>Y=qSg>Ik
|u_fVQj
return n; 'H-hp
} FE3uNfQs|
9=.7[-6i9
sGO+O$J
} F!zGk(Pu
{Lugdf'
u-@;Q<v$
/* NS){D7T
**SiteInfoBean.java ,*Wp$
*/ %hi]oz
package NetFox; &?Z<"+B8S
P1dFoQz
q+{yv
public class SiteInfoBean { [E)&dl_k
[i8Ju
0.0r?T
private String sSiteURL; //Site's URL JQ9+kZ
private String sFilePath; //Saved File's Path 8f>v[SQ"
private String sFileName; //Saved File's Name iM M s3
private int nSplitter; //Count of Splited Downloading File ?\_vqW
lY[\eQ 1:
Qb8Z+7
public SiteInfoBean() o]@'R<F(u
{//nSplitter的缺省值为5 =}'7}0M_=
//default value of nSplitter is 5 2?kVbF
this("","","",5); D*t[5,~j
} EAV6qW\r5]
+Ou<-EQV
g1I8_!}~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~T!D:2G
{ @T] G5|\ok
sSiteURL= sURL; H $mZ?
sFilePath = sPath; ~toR)=Yv
sFileName = sName; <4P.B?-/t
this.nSplitter = nSpiltter; X3HJ3F;==
]T._TZ"
TecWv@.
} ~h$ H@&5
kH?PEA! \
g ,yB^^%
public String getSSiteURL() 0s6eF+bs
{ rh T!8dTk
return sSiteURL; 83F]d+n
} 2]}e4@{
~?B\+6<V
*~^%s+b
public void setSSiteURL(String value) |WSmpuf
{ q#`;G,rs
sSiteURL = value; YGhHIziI
} 3935cxT1U
A_+*b [P
E//*bmww
public String getSFilePath() +1Pu29B0
{ i}@5<&J
return sFilePath; ~zDFL15w
} [Vj|fy4
!X 0 (4^
^+Njz{rpG
public void setSFilePath(String value) ZVz*1]}
{ xLw[ aYy4
sFilePath = value; ?uXY6J"
} \b?O+;5Cj
8KWhXF
0$|wj^?U
public String getSFileName() wD SSgk
{ =6BI[_0
return sFileName; =<U'Jtu6'
} ~TjTd
r]&&*:
t}gK)"g
public void setSFileName(String value) 9\i^.2&
{ ]o`FF="at
sFileName = value; hcQv!!Q"k$
} `7'=~BP?X
qGgdWDn`
>k(AQW5?
public int getNSplitter() kaVYe)~
{ MsA)Y
return nSplitter; >|JMvbje
} 7` t,
OgkbN`
CxVrnb[`q
public void setNSplitter(int nCount) op|x~Thf
{ bfA9aT
nSplitter = nCount; Wl3fR[@3Q
} M:w]g`LKl
} m\ /V0V\
G_?qY#"(
O9F#gO|!
/* @m"P_1`*
**Utility.java 92L{be;SY
*/ 5@~5RNrq2
package NetFox; IF|%.%I$!U
S]biN]+7s
}Yp]A
public class Utility { 2LH.If
2graLJ?9Z
9_pOV%Qs
public Utility() P87qUC
{ 6Q9S~YYq
Q |^c5
L!kbDbqn
} Ib$?[
;EfREfk
//线程睡眠 kam\dn04
public static void sleep(int nSecond) !,PoH
{ a5%IjgQ&z
try{ T8a!"lPP7
Thread.sleep(nSecond); Z6oA>D
} 0G/_"}@
catch(Exception e) )UG<KcdI
{ )rv<"
e.printStackTrace (); 84maX'
} 44cy_
} TzK[:o
h`/1JjP
//日志 Toc="F`SW
public static void log(String sMsg) W>`#`u
{ [7SR2^uf<j
System.err.println(sMsg); =%oKYQ
} j0[9Cj^%c
KR/SMwy
d<4q%y'X{
public static void log(int sMsg) $9O%,U@
{ 00@y,V_]
System.err.println(sMsg); Tta+qjr
} @60/IE{-v
} -m>ng E~q
q3R?8Mb
kc70HrG
/* 4f> s2I&pQ
**TestMethod.java BA|*V[HBE
*/ `1"Xj ^ YM
package NetFox; w B[H&
+46?+kKt
3L(vZ2&
public class TestMethod { {F+iL&e)
n:[GK_
9dD;Z$x&Xk
public TestMethod() zAdZXa[MRY
{ ///xx/weblogic60b2_win.exe .m\'|%
try{ ^{Y9!R*9U*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0|_d{/VK4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); au 5qbP
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;p'Ej'E
fileFetch.start(); 6H}8^'/u
} Qape DU;
catch(Exception e){e.printStackTrace ();} G[5z3
F%>`?NG+c
3F6=/
} C!}9[X!7@:
u|]`gsFZ\
%t\~3pw=
public static void main(String[] args) MUd 9R
{ 'VTLp.~G~
new TestMethod(); rfS kQT
} <:UP
} <v=T31aS
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