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)); +>F #{b
} 0>E0}AvkT
for(int i=0;i<nEndPos.length-1;i++) 0Q]p#;
{ %?4G^f
nEndPos = nStartPos[i+1]; !Gphs`YI
} P@u&~RN9f+
nEndPos[nEndPos.length-1] = nFileLength; A(xCW+h@)
} (4U59<ie
} Ix"hl0Kh
[\j@_YYd
Tath9wlv6;
//启动子线程 7=o2$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4/Vy@h"A3
for(int i=0;i<nStartPos.length;i++) wR"4slY_%
{ 4sVr]p`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dwQ*OxFl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T@GR Tg
nStartPos,nEndPos,i); ()E:gqQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0'DlsC/`*
fileSplitterFetch.start(); /R_*u4}iD
} /$IF!q+C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), is3nLm(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cI5*`LML1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #&@qmps(T
nEndPos = " + nFileLength); O$><E8q
// fileSplitterFetch[nPos.length-1].start(); t*fG;YOg
+3c!.] o;
x bG'![OX
//等待子线程结束 %Jrdr`<
//int count = 0; NMSpi[dr
//是否结束while循环 UL/|!(s
boolean breakWhile = false; O\5*p=v
]g>@r.Nc
%HRFH
while(!bStop) >PsP y.
{ 3wS{@'
write_nPos(); ! Z e
Utility.sleep(500); S;o U'KOY
breakWhile = true; )$#r6fQO
dh7PpuN{
!U,^+"l'GP
for(int i=0;i<nStartPos.length;i++) -jZP&8dPH
{ 3X+uJb2
if(!fileSplitterFetch.bDownOver) !Q,A#N(
{ S=Ihg
breakWhile = false; @~!1wPvF`I
break; 5-277?
} seFug
} <JA`e+Bi
if(breakWhile) hIj[#M&6
break; L`i#yXR
+s6wF{
${$XJs4
//count++; (8!#<$
//if(count>4) iL-I#"qT,
// siteStop(); 7k<4/|CQ{
} 6~b~[gA
)e)@_0
o:\RJig<
System.err.println("文件下载结束！"); TtL2}Wdd.%
} o W)M&$oS
catch(Exception e){e.printStackTrace ();} n'/w(o$&
} :!a9|Fh~
:<%q9)aPf`
n2bL-
//获得文件长度 n6gYZd
public long getFileSize() B|IQ/g?
{ i<g|+}I
int nFileLength = -1; (89NK]2x
try{ o7feH 6Sh
URL url = new URL(siteInfoBean.getSSiteURL()); .+G),P)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U*ZP>Vv
httpConnection.setRequestProperty("User-Agent","NetFox"); Ae,-.xJ
&bx;GG\<4
YyX/:1 sg>
int responseCode=httpConnection.getResponseCode(); \TG!M]D:
if(responseCode>=400) ]E66'
{ A9!gww
processErrorCode(responseCode); , #yE#8
return -2; //-2 represent access is error xMsos?5}
} w5l:^^zF(
K\&A}R
{xw*H<"f<
String sHeader; '0|AtO77
9.|+KIRb
d"nz/$
for(int i=1;;i++) 47_4`rzy;
{ ?~rF3M.=|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O)MKEMuA
//Utility.log(in.readLine()); QD LXfl/
sHeader=httpConnection.getHeaderFieldKey(i); lrjlkgSN
if(sHeader!=null) ,P^pDrc
{ Z*d8b
if(sHeader.equals("Content-Length")) #&.&Uu$
{ d:0RDK-}s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AElx #`T
break; [L1pDICoy
} >n@?F[Y
} c'_-jdi`>_
else ;T2)nSAqt
break; wTFM:N
} 'kc_OvVA
} /)SwQgK#
catch(IOException e){e.printStackTrace ();} ?@9kVB*|
catch(Exception e){e.printStackTrace ();} r)<]W@Pr
:Ia3yi#
Ebp^-I9.d
Utility.log(nFileLength); 8NJ(l
@<--5HbX
Nt#zr]Fz
return nFileLength; TH2D;uv
} .+7GecYz
:g3n [7wR
n.C.th >Y1
//保存下载信息（文件指针位置） <ns[( Q
private void write_nPos() BVxg=7%St
{ Q7$ILW-S
try{ N<+ ><>9
output = new DataOutputStream(new FileOutputStream(tmpFile)); %4U;Rdq&Ud
output.writeInt(nStartPos.length); S\GC^ FK
for(int i=0;i<nStartPos.length;i++) ?eT^gWX
{ L)VEA8}
// output.writeLong(nPos); )((Jnm D
output.writeLong(fileSplitterFetch.nStartPos); 2%N$Y]
output.writeLong(fileSplitterFetch.nEndPos); #NVtZs!V/
} U9IP`)z_5t
output.close(); ;]?1i4p)
} 693J?Yah[
catch(IOException e){e.printStackTrace ();} I#Ay)+D
catch(Exception e){e.printStackTrace ();} $rDeI-)S
} @D8c-`LC"*
rX6"w31
m;{_%oQ;
//读取保存的下载信息（文件指针位置） K1Nhz'^=D
private void read_nPos() .]%PnJM9K
{ qIK"@i[ uq
try{ I!.o&dk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Rd;k>e
int nCount = input.readInt(); 7]YLe+Ds
nStartPos = new long[nCount]; <3z]d?u
nEndPos = new long[nCount]; PygT_-3z{
for(int i=0;i<nStartPos.length;i++) $78fR8|r-
{ PJN TIa
nStartPos = input.readLong(); dg 0`0k
nEndPos = input.readLong(); z %` \p
} T%K(opISc(
input.close(); tfj6#{M5
} i$)bZr\
catch(IOException e){e.printStackTrace ();} &^4\Rx_I
catch(Exception e){e.printStackTrace ();} L5""
} r_T\%
}% JLwN
T F&xiL^
private void processErrorCode(int nErrorCode) Z}.N4 /
{ wly#|
System.err.println("Error Code : " + nErrorCode); |$#u~<r_ w
} Ixg.^>62
KDgJ~T
M(x5D;db/
//停止文件下载 `?{QCBVj
public void siteStop() i4 KW
{ 7 2ux3D
bStop = true; p>=YPi/d
for(int i=0;i<nStartPos.length;i++) ?8. $A2(Xw
fileSplitterFetch.splitterStop(); *PE1)bF
@jO3+
j]}A"8=1
} q=ZLSBZ
} 2V_C_5)1
//负责部分文件的抓取 Y$!K<c k
**FileSplitterFetch.java `h_,I R<
*/ oAe]/j$
package NetFox; ]K0<DO9
UA/Q3)
mv%fX2.
import java.io.*; lz@fXaZM
import java.net.*; ZO{uG(u
zx'G0Z9]
-EFtk\/
public class FileSplitterFetch extends Thread { 64>E|w
jDIO,XuF
|Y"q. n77
String sURL; //File URL 5b3Wt7
long nStartPos; //File Snippet Start Position <~t38|Ff@
long nEndPos; //File Snippet End Position H1rge<
int nThreadID; //Thread's ID z$oA6qB)
boolean bDownOver = false; //Downing is over z:bxnM2\
boolean bStop = false; //Stop identical <",4O
FileAccessI fileAccessI = null; //File Access interface 4m$nVv
,x!P|\w.G{
[sp=nG7i&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Rv ?Go2
{ Ji4c8*&Jpc
this.sURL = sURL; FOgF'!K
this.nStartPos = nStart; sXOGIv
this.nEndPos = nEnd; 7g_:Gv~v
nThreadID = id; ?JDZDPVJ)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !YSAQi;I
} NqvL,~1G
~PP*k QZlJ
T{d7,.:
public void run() $-YS\R\9x
{ +Sv`23G@
while(nStartPos < nEndPos && !bStop) !OekN,6
{ TAlpy$
&K2[>5 mG
} WY7!Y
try{ PcC9)x
URL url = new URL(sURL); p>h B&h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2<)63[YO
httpConnection.setRequestProperty("User-Agent","NetFox"); Fh9`8
String sProperty = "bytes="+nStartPos+"-"; .,(bDXl?
httpConnection.setRequestProperty("RANGE",sProperty); "AP''XNi
Utility.log(sProperty); He^+>XIam
YUJlQ2e(
VS@o_fUx)
InputStream input = httpConnection.getInputStream(); kX."|]
//logResponseHead(httpConnection); E8J`7sa
+Tc<|-qQn
OsPx-|f S~
byte[] b = new byte[1024]; zI8Q "b
int nRead; A>(m}P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *,{. oO9#
{ ;H/*%2
nStartPos += fileAccessI.write(b,0,nRead); RN238]K
//if(nThreadID == 1) &^FCp'J-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iq-n(Rfw~
} 2-j+-B|i
,.uu/qV}w
RzQ1Wq
Utility.log("Thread " + nThreadID + " is over!"); 55MsF}p
bDownOver = true; 8:0QIkqk
//nPos = fileAccessI.write (b,0,nRead); 3]WIN_h
} =_I2ek
catch(Exception e){e.printStackTrace ();} %/b?T]{
} RoSh|$JF
} o1YX^-<[F
'x{g P?.
<iunDL0
//打印回应的头信息 i%+cPQ^o
public void logResponseHead(HttpURLConnection con) 9V`/zq?
{ SLpB$puS
for(int i=1;;i++) $r*7)/
{ st P~/}
String header=con.getHeaderFieldKey(i); csz/[*
if(header!=null) `4__X;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /9NQ u
Utility.log(header+" : "+con.getHeaderField(header)); f305yo
else I]bqle0M
break; evNo(U\C
} I!&|L0Qq
} )9MmL-7K
T^g2N`w2
Rnt&<|8G
public void splitterStop() 6js94ko[
{ Iq0_X7:{QI
bStop = true; asb-syqU
} *,5V;7OR
<uDEDb1|l
w'z?1M(*
} #y%bx<A
Q( .d!CQ>
J*$u
/* )$Xd#bzD|
**FileAccess.java A9\m.3jo
*//文件访问(定位，写) Y,?s-AB
package NetFox; Ks.m5R
import java.io.*; u"XqWLTV
=k6zUw;5 U
}Iz'#I Xx
public class FileAccessI implements Serializable{ +gqtW86
\.y|=Ql_u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IJ2]2FI
RandomAccessFile oSavedFile; -jnx0{/
long nPos; W.TZU'%
87P{vf#
[~9rp]<
public FileAccessI() throws IOException '#gd19#
{ ]C_g:|q
this("",0); jOj`S%7
} 7yo/sb9h
X5UcemO
B?9K!c
public FileAccessI(String sName,long nPos) throws IOException 9~98v;Z1
{ 3IQ)%EN
oSavedFile = new RandomAccessFile(sName,"rw"); <-62m8N|
this.nPos = nPos; &S}%)g%Iv9
oSavedFile.seek(nPos); n0g,r/
} H_KE^1
rq?:I:0
Qg;A (\z
public synchronized int write(byte[] b,int nStart,int nLen) O^ZOc0<
{ 4of3#M
int n = -1; Ac;rMwXk#
try{ qOYCQ
oSavedFile.write(b,nStart,nLen); rStfluPL
n = nLen; vKN"o* q
} 3-#|6khqt
catch(IOException e) O9*cV3}H
{ ss63/
e.printStackTrace (); O4@sN=o
} =xcA4"k
im{'PgiR
ON#\W>MK?
return n; y%)5r}S^
} .4Ob?ZS(
>ch{u{i6
{vYmK#}
} Dz/I"bZLC
jV Yt=j*"V
+^tq?PfE
/* KD?~ hpg
**SiteInfoBean.java `l,=iy$
*/ 6}^0/76^,
package NetFox; d2lOx|jt
k_%2Ok
b);Pw"_2
public class SiteInfoBean { RaT(^b(
n B4)%
y;Xb."e~
private String sSiteURL; //Site's URL sPY*2B
private String sFilePath; //Saved File's Path n^P=a'+
private String sFileName; //Saved File's Name \hN\px
private int nSplitter; //Count of Splited Downloading File dK'?<w$
V&`\ s5Q
-BUxQ8/,
public SiteInfoBean() cAq>|^f0a
{//nSplitter的缺省值为5 #~?Q?"
//default value of nSplitter is 5 >!O3 jb k
this("","","",5); KtzoL#CT
} hZ2!UW4'
f1MKYM%^x
'7G'R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <,p|3p3
{ *O-1zIlp
sSiteURL= sURL; bOjvrg;Sz\
sFilePath = sPath; Poy ]5:.
sFileName = sName; fP>_P#gZ
this.nSplitter = nSpiltter; 0VC8'6S_k
.,zrr&Po
yoa"21E$
} xLX<.z!r
58\rl G
#(&!^X3
public String getSSiteURL() usEdp
{ gQaBQq9
return sSiteURL; 9EzXf+f
} P5s'cPX
J'^H@L/E
"?EoYF_
public void setSSiteURL(String value) 5=%:CN!/@p
{ ixF '-
sSiteURL = value; +F3@-A
} hZNS$
vQB;a?)o
C9zQ{G
public String getSFilePath() y1R53u`;L
{ K{)N:|y%!$
return sFilePath; 1}+lL)-!
} 1A\Jh3;Q
i zJa`K
mh`~1aEr
public void setSFilePath(String value) \jLn5$OW
{ 0S8v41i6
sFilePath = value; ]la8MaZ<
} JJ@O5
A41*4!L=
$g&,$7}O_
public String getSFileName() !G E-5\*
{ I;iJa@HWQ
return sFileName; SrGX4
} *olV Y/'O
gyi<ot;
1{@f:~v?
public void setSFileName(String value) Uywi,9f
{ !K a!f1
sFileName = value; iXt1{VP'K
} J.'}R2gT1
dw{L,u`68
1L722I@
public int getNSplitter() ,)%al76E
{ ELoE-b)Cb
return nSplitter; o,l3j|1
} dL;C4[(N
%oVoE2T{@
q]Y [W1
public void setNSplitter(int nCount) 4oW6&1
{ Y1RiuJtL
nSplitter = nCount; ?EP>yCR9
} 1F?`.~q
} L=Cm0q 3v
A0{ !m
y4* }E
/* 3LXS}~&
**Utility.java *s4h tt
*/ zK.%tx}+=k
package NetFox; R T/T+Q!
A[20ic
mqL&bmT
public class Utility { iW.4'9
5Y<O
]BAM _
public Utility() (p4|,\+
{ 9_yO6)`
}{"a}zOl
-={Z::}S"
} tMM*m
0I6[`*|SX
//线程睡眠 xEv]VL:
public static void sleep(int nSecond) ?kBi9^)N4
{ AQX~do\A
try{ Vs@[="
Thread.sleep(nSecond); AITV+=sN
} #$q~ZKB
catch(Exception e) 1=LI))nV
{ TAfLC)
e.printStackTrace (); 5 :O7cBr
} m$nT#@l5bH
} C1=7.dPr
^R\et.W`s
//日志 !OwRx5
public static void log(String sMsg) :4 9ttJl
{ R.n:W;^`
System.err.println(sMsg); EC[2rROn\
} 3Z?"M
>KF1]/y<
*n9t~t6GHg
public static void log(int sMsg) so[i"ZM)
{ pfd||Z
System.err.println(sMsg); {}F?eI
} .hI3Uv8[
} z?o16o-:
r$3{1HXc
nNbOq[
/* RmXC ^VQ
**TestMethod.java "#7~}ZB
*/ z"4UObVs
package NetFox; ~!o\uTVr
^kg[n908Nw
#H]cb#
public class TestMethod { 32DT]{-N!
CXC,@T
S3cjw9V
public TestMethod() 8?ig/HSt2
{ ///xx/weblogic60b2_win.exe C@!C='b,
try{ z}I4m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,E&PIbDL1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r{DR$jD
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8m? 9?OV5
fileFetch.start(); eK_Q>;k5A
} |e+8Xz1>
catch(Exception e){e.printStackTrace ();} S`,(10Y
Y\e,#y
]Z/<HP$#
} z#qlu=
\i Ylh HD
M%dJqwH5{
public static void main(String[] args) s>}ScJZK
{ HsA4NRF'7
new TestMethod(); u\~dsD2)q
} r;3{%S._
} j$Ttoo
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