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)); z4fK{S
} ]:#$6D"
for(int i=0;i<nEndPos.length-1;i++) wkpVX*DfRE
{ Mc3h R0
nEndPos = nStartPos[i+1]; *U^I`j[u
} d\Z4?@T<5
nEndPos[nEndPos.length-1] = nFileLength; lRK?%~
} Z6AU%3]
} L8K3&[l%
3Co>3d_
Cwa0!y5%
//启动子线程 ?&nz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L#@$Mtc
for(int i=0;i<nStartPos.length;i++) w>UV\`x
{ dZYJ(7%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Jpd9KK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Oc+L^}elJ
nStartPos,nEndPos,i); 4_:e+ ql
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); td$6:)
fileSplitterFetch.start(); xENA:j?kF
} ~HI0<;r=eL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s ;Nu2aOp7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XUNgt(OGR'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", & ~G
nEndPos = " + nFileLength); ;B7|tajd
// fileSplitterFetch[nPos.length-1].start(); G8-d%O p
5e8-?w%e
g\nL n#
//等待子线程结束 AezXou&
//int count = 0; ';!UJWYl
//是否结束while循环 "m)O13x
boolean breakWhile = false; \mit&EUh}
A_ z:^9
p 8Hv7*
while(!bStop) Y tj>U
{ _r)nbQm&
write_nPos(); 4IE#dwZW
Utility.sleep(500); W&[9x%Ba
breakWhile = true; Jpnp'
.@Sh,^v
RXvcy<
for(int i=0;i<nStartPos.length;i++) H$iMP.AK
{ \/%Q PE8
if(!fileSplitterFetch.bDownOver) u}0t`w:
{ xW )8mv?4n
breakWhile = false; `fVA.%
break; -*j;
} ]@]"bF!Dn
} iv`-)UsE
if(breakWhile) sJYX[
break; jo:p*Q"F
~;a* Oxt
?UIb!k>
//count++; NPq2C8:
//if(count>4) oYm"NDS_.
// siteStop(); hrxASAfg6
} iU|C<A%Hh
Ek\Zi#f<
w5R9\<3L
System.err.println("文件下载结束！"); YWd(xm"4
} kQcQi}e
catch(Exception e){e.printStackTrace ();} fP*C*4#X
} j+v)I=
X,Q(W0-6$u
j}Mpc;XOc
//获得文件长度 M/ \~
public long getFileSize() BNLall
{ SK2pOZN
int nFileLength = -1; #Z5~a9rO
try{ "lMWSCas
URL url = new URL(siteInfoBean.getSSiteURL()); PkO(Y!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6n4S$a
httpConnection.setRequestProperty("User-Agent","NetFox"); \EqO;A%<
,peFNpi
0(.C f.B~
int responseCode=httpConnection.getResponseCode(); of<OOh%3
if(responseCode>=400) DvKMb-*S
{ S+ x[1#r
processErrorCode(responseCode); U_04QwhK7
return -2; //-2 represent access is error A]slssE+
} N* QI>kzU
#`EMK
L>*|T[~
String sHeader; ;!Mg,jlQ
ttxOP
hTqJDP"&F
for(int i=1;;i++) Cr"hu;
{ svII =JB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xp@OIn
//Utility.log(in.readLine()); .- o,_eg1f
sHeader=httpConnection.getHeaderFieldKey(i); p_5+L@%Gb
if(sHeader!=null) ={d\zjI$
{ .4-S|]/d,
if(sHeader.equals("Content-Length")) 4cL=f
{ oWT0WS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GR9F^Y)K{
break; 0_)\e
} NIGFu{S
} _TiF}b!hi
else 3J{'|3x
break; "^7Uk#! 7
} Ro69woU
} ZGBcy}U(k
catch(IOException e){e.printStackTrace ();} r>OE[C69
catch(Exception e){e.printStackTrace ();} 9)`wd&!
_;+&'=6.[
:I8t}Wg
Utility.log(nFileLength); 1,,:4*)
~M=`f{-$K
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return nFileLength; Si(?+bda0c
} }r[BME
[\y>Gv%
jLU)S)
//保存下载信息（文件指针位置） SX.v5plhc
private void write_nPos() XPSWAp)
{ G%{jU'2
try{ fzcT(y
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xb {y*',
output.writeInt(nStartPos.length); 2oRmro
for(int i=0;i<nStartPos.length;i++) F ry5v?22
{ 1U!CD-%(
// output.writeLong(nPos); /6fsh7 \
output.writeLong(fileSplitterFetch.nStartPos); hvwr!(|W
output.writeLong(fileSplitterFetch.nEndPos); -`JY] H
} N[%IrN3
output.close(); Ex{]<6UAu
} K>U&jH
catch(IOException e){e.printStackTrace ();} (G Y`O
catch(Exception e){e.printStackTrace ();} /nNHI34
} %1<|.Dmd
+Y+kx"8
H3b`)k sFr
//读取保存的下载信息（文件指针位置） "7d_$.Z
private void read_nPos() MH-,+-Eq
{ !`o=2b=N
try{ "|H0 X#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >ZT3gp?E
int nCount = input.readInt(); psBBiHB[L
nStartPos = new long[nCount]; 6/)A6Tt
nEndPos = new long[nCount]; Cq=c'(cX
for(int i=0;i<nStartPos.length;i++) Yi3DoaS;"
{ kBkhuKd)V
nStartPos = input.readLong(); +=QboUN
nEndPos = input.readLong(); TqC"lO>:Q
} 43YusUv
input.close(); 4_eq@'9-q
} BR*U9K|W
catch(IOException e){e.printStackTrace ();} G!uxpZ
catch(Exception e){e.printStackTrace ();} wS*UXF&f
} te_D ,
.$rcTZ
G9]GK+@&F
private void processErrorCode(int nErrorCode) '?nhpT^
{ u<[Y6m
System.err.println("Error Code : " + nErrorCode); l%fl=i~oN
} ;iWCV&>w
W NCdk$
xE:p)B-]
//停止文件下载 :v+39
public void siteStop() zB4gnVhus|
{ juM?y'A
bStop = true; &j$k58mX
for(int i=0;i<nStartPos.length;i++) :DEZ$gi
fileSplitterFetch.splitterStop(); mOBS[M5*
59|Tmf(dS;
MZ.Jkf(
} A-kI_&g\Og
} +Z+]Tqo
//负责部分文件的抓取 2X:n75()
**FileSplitterFetch.java pq4frq
*/ j`bOJTBE
package NetFox; V@F~Cx
n#iL[ &/Aw
z`W$/tw"
import java.io.*; Y,{Xv
import java.net.*; K-/fq=z
s;L7 _.hH@
D n^RZLRhy
public class FileSplitterFetch extends Thread { ~*RNJ
h c"n?
3OTSLF/
String sURL; //File URL #'8E%4
long nStartPos; //File Snippet Start Position 6<2 7}S
long nEndPos; //File Snippet End Position y3lsAe#
int nThreadID; //Thread's ID 8ARpjYZP
boolean bDownOver = false; //Downing is over Q~`n%uYg\{
boolean bStop = false; //Stop identical Oo,<zS=ICk
FileAccessI fileAccessI = null; //File Access interface Pp?J5HW
,JR7N_"I
B<W{kEY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2`x[y?Tn
{ NVQIRQ.
this.sURL = sURL; r__uPyIMG/
this.nStartPos = nStart; =2< >dM#`
this.nEndPos = nEnd; 75a3H`
nThreadID = id; h_J'dJS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,+f'%)s_x
} KV Mm<]Z
EBJaFz'
y5>H>NS
public void run() *9G;n!t
{ SJL?(S*
while(nStartPos < nEndPos && !bStop) 9R!.U\sq
{ WVKzh
cxVnlgq1
,+0_kndR
try{ dx|j,1e
URL url = new URL(sURL); {'JoVJKv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0q81H./3
httpConnection.setRequestProperty("User-Agent","NetFox"); f"S^:F0
String sProperty = "bytes="+nStartPos+"-"; [H!V
httpConnection.setRequestProperty("RANGE",sProperty); 2x0[@cTi?
Utility.log(sProperty); V5m4dQ>t
uSH.c>
(JOge~U
InputStream input = httpConnection.getInputStream(); 1aKY+4/G
//logResponseHead(httpConnection); qWdL|8
[W` _`
2\_}81hM
byte[] b = new byte[1024]; /K1YDq<=
int nRead; v. !L:1@I.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H_Vf_p?
{ #49,7OBU
nStartPos += fileAccessI.write(b,0,nRead); JpN+'/
//if(nThreadID == 1) Fq:BRgCE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S'q (Qo
} 0I1bY]*
^2=11
@#;2P'KL
Utility.log("Thread " + nThreadID + " is over!"); t ?rUbN
bDownOver = true; Y}QtgZEt
//nPos = fileAccessI.write (b,0,nRead); a=Pl3Uo
} du Pzt
catch(Exception e){e.printStackTrace ();} U2seD5I
} w(0's'
} ]FP(,:Yw
R]H/Jv\'
}9=VhC%J
//打印回应的头信息 Bg{"{poy
public void logResponseHead(HttpURLConnection con) -Z9e}$q$,
{ JHBX'1GQa
for(int i=1;;i++) sSU p7V
{ 26?yEd6^Z
String header=con.getHeaderFieldKey(i); pkQEry&Z
if(header!=null) n'>`2 s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #fd;]
Utility.log(header+" : "+con.getHeaderField(header)); bejvw?)S.
else |bA\>%~
break; 3U^E<H
} Xf(H_&K
} qf-0 | w
rZEL7{
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public void splitterStop() f5'Cq)Vw_
{ _NA[g:DZ&O
bStop = true; :+06M@
} K 0R<a~
S}WQ~e
{oOzXc6o
} hV_bm@f/y
8R0Q-,'
'W(!N%u
/* 1ayL*tr
**FileAccess.java jOV,q%)^,:
*//文件访问(定位，写) EdR1W~JZ
package NetFox; KPTp91
import java.io.*; xY v@
xvU@,bzz
F/}(FG<'>I
public class FileAccessI implements Serializable{ WTK )SKa,.
W!6&T [j>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mwm9{1{
RandomAccessFile oSavedFile; cHP~J%&L
long nPos; <a_ytSoG1
I54`}Npp
iW oe
public FileAccessI() throws IOException |T3F:],`
{ 2z#gn9Wb
this("",0); oy{ {d
} (@X].oM^y
TuR.'kE@
`,~8(rIM
public FileAccessI(String sName,long nPos) throws IOException Ts)ox}rYVm
{ Y~,ZBl,
oSavedFile = new RandomAccessFile(sName,"rw"); HFlMx
this.nPos = nPos; 6)5Akyz4V
oSavedFile.seek(nPos); A}"aH
} fRlO.!0(
jxeZ,w o
9\f%+?p
public synchronized int write(byte[] b,int nStart,int nLen) f~a]og5|G
{ iTUOJ3V7i
int n = -1; _e4%<!1
try{ ( &N`N1
oSavedFile.write(b,nStart,nLen); q#pD}Xe$
n = nLen; 2":{3=oW~
} %OT}r
catch(IOException e) #z$g1\v
{ Cg#@JuwHa
e.printStackTrace (); T'8d|$X
} L JW0UF|
s[2>r#M
MbbKo-7F$
return n; ` b$u w
} h_*!cuH
}LYK:?_/
_|1m]2'9
} Wy:xiP
MVDEVq0
0vYHx V
/* ^p7g[E&
**SiteInfoBean.java lE|Hp
*/ 7gxC xfL$
package NetFox; Cr&,*lUo
=pa F6!AB
R%EpF'[~[
public class SiteInfoBean { <36z,[,kZ@
Ng,<4;
qL;u59
private String sSiteURL; //Site's URL K (px-jY
private String sFilePath; //Saved File's Path LWX,u
private String sFileName; //Saved File's Name HEBKRpt
private int nSplitter; //Count of Splited Downloading File jVdRy{MH
?mq<#/qb
d$f3Cre
public SiteInfoBean() aWg*f*2f
{//nSplitter的缺省值为5 Z4VNm1qs
//default value of nSplitter is 5 md S`nhb
this("","","",5); <0sT
} GI.=\s
B QxU~s
.=`r?#0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0D==0n
{ v$JhC'
sSiteURL= sURL; e^%>_U
sFilePath = sPath; hf('4^
sFileName = sName; |i~Ab!*8n
this.nSplitter = nSpiltter; DuvI2ZWP]
(?W[#.=7
oj$^87KX
} A(2!.Y 2?*
:*g3PhNE
xPp\OuwK
public String getSSiteURL() ?yNg5z
{ 1w~@'ZyU
return sSiteURL; I%?ia5]H
} wgPkSsuBuC
!8jr $
N.1@!\z@@
public void setSSiteURL(String value) h+d \u
{ u&-Zh@;Q7
sSiteURL = value; ?7|6jTIs
} ]ucz8('
X}5}M+'~
xtq='s8e
public String getSFilePath() P\k5%
{ \:/~IZdzF
return sFilePath; rf\A[)<:
} &Cykw$s
_$vAitUe4S
0x1#^dII
public void setSFilePath(String value) jt6q8
{ KEfx2{k b
sFilePath = value; rEfo)jod
} 3v?R"2\qS
aePLP
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public String getSFileName() TQ`4dVaf
{ ^hyY,X
return sFileName; k.@OFkX.
} {9_}i#,vR
K.l7yBm
552yzn1
public void setSFileName(String value) ipi^sCYp
{ _&U.DMt2 C
sFileName = value; ~jOn)jBRZ
} OA?pBA
Uja`{uc
lKT<aYX
public int getNSplitter() xsN)a!
{ 9*b(\Z)N
return nSplitter; p*ic@n*G
} rAwuWM@BIg
:GBM`f@
m]"13E0*x
public void setNSplitter(int nCount) fBw"<J{
{ Tj3xK%K_r3
nSplitter = nCount; a 9H^e<g
} ;jZfVRl
} E(p*B8d
qh)10*FB
!M*$pQi}
/* XI/LVP,.
**Utility.java kaG@T,pH(
*/ &CcUr#|
package NetFox; s%OPoRE
\LbBK ~l-I
VX{9g#y$j
public class Utility { 1RM@~I$0
PYhRP00}M
2M`:/shq
public Utility() a\]glw\;
{ HA#9y;\
m6 VL
edZhI
} eWw# T^
;GF+0~5>
//线程睡眠 o1^Rx5
public static void sleep(int nSecond) $AyE6j_1gX
{ _Gb O>'kE
try{ X={Z5Xxr"
Thread.sleep(nSecond); w;=g$Bn
} *%p`Jk-U
catch(Exception e) H7Y :l0b
{ 0~( f<:
e.printStackTrace (); Z6\H4,k&
} d:&=|kKw
} cy{ ado2
QRFBMq}'
//日志 .d?2Kc)SV\
public static void log(String sMsg) @en*JxIM
{ !QXPn}q^0
System.err.println(sMsg); i[7<l&K]
} 2M$^|j:[
n=1_-)
8{)j"rghah
public static void log(int sMsg) l1#F1q`^t
{ }T1.~E
System.err.println(sMsg); FA7q pc
} ~[ZRE @
} 3<A$lG
qC4Q+"'
`-)Hot)
/* 1n-+IR"
**TestMethod.java FofeQ
*/ A(v5VvgZE
package NetFox; {1Hs5bg@
Q xm:5P
)0UXTyw^
public class TestMethod { ~M Mv+d88
AR?1_]"=
a]4h5kJ';
public TestMethod() 'fS&WVR?
{ ///xx/weblogic60b2_win.exe i8Xz'Sw07
try{ FhJtiw@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6*r#m%|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zog&:]P'F
SiteFileFetch fileFetch = new SiteFileFetch(bean); fMluVND
fileFetch.start(); `2l j{N
} b-Xc6f
catch(Exception e){e.printStackTrace ();} J*nWCL
1ww#]p`1
mi'3ibCG
} ~/m=Q<cV
dW#T1mB
5h7M3s
public static void main(String[] args) ,We'AR3X
{ -.t/c}a#
new TestMethod(); ^=@`U_(,G
} \.K4tY+V
} 7M,(!*b
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