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)); +uay(3m((
} _zlqtO
for(int i=0;i<nEndPos.length-1;i++) J+rCxn?;g
{ V5+SWXZ
nEndPos = nStartPos[i+1]; HhO".GA
} A-:O`RK
nEndPos[nEndPos.length-1] = nFileLength; %ZHP2j %~
} oFjIA!
} ;&H4u)
z/i+EE
21k5I #U
//启动子线程 r0p w_j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YK|bXSA[
for(int i=0;i<nStartPos.length;i++) [MuEoWrq(}
{ t78k4?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I*9e]m"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x.Q&$#
nStartPos,nEndPos,i); vJAZ%aW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !9 fz(9
fileSplitterFetch.start(); Gt9&)/#
} IV\J3N^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2WUT/{:X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *~w[eH!!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]HpA5q1ck
nEndPos = " + nFileLength); ~?B;!Csk
// fileSplitterFetch[nPos.length-1].start(); 'SQG>F Uy
(sVi\R
nUkaz*4qU
//等待子线程结束 '_|h6<.k[
//int count = 0; XL7h}
//是否结束while循环 lu Q~YjH
boolean breakWhile = false; aF03a-qw<
cuOvN"nuNj
%Uz(Vd#K
while(!bStop) =8U&[F
{ R<B7K?SxV~
write_nPos(); 7GDHz.IX
Utility.sleep(500); kdGT{2u
breakWhile = true; ,3nN[)dk
OY?y^45y
JN7k2]{
for(int i=0;i<nStartPos.length;i++) !^Q.VYY
{ @&[T _l
if(!fileSplitterFetch.bDownOver) Y@PI {;!
{ /x3/Ubmz~x
breakWhile = false; l<M'=-Y
break; bH"hX
} {BKl`1z
} j0@[Br%7
if(breakWhile) IIy~[4dW
break; ~'R(2[L!;
$s<Ne{?
McPNB`.H
//count++; y8fsveX
//if(count>4) ;5@ t[r
// siteStop(); xe/(
} {rcnM7 S1L
=y=cW1TG
}NsUnbxT
System.err.println("文件下载结束！"); =J1rlnaaEL
} #-h\.#s
catch(Exception e){e.printStackTrace ();} c'*a{CV4P
} T?4G'84nN
8i?l02
Qt|c1@J
//获得文件长度 EUIIr4]
public long getFileSize() .!JVr"8
{ 4 B*0M
int nFileLength = -1; &w=3^
try{ xLx]_R()
URL url = new URL(siteInfoBean.getSSiteURL()); O:da-xWJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p ;|jI1
httpConnection.setRequestProperty("User-Agent","NetFox"); < y*x]}
m*mm\wN5
|ae975
int responseCode=httpConnection.getResponseCode(); EM\'GW
if(responseCode>=400) NKQOUw:qn
{ hR.@b*q?R
processErrorCode(responseCode); L<fvKmo(fw
return -2; //-2 represent access is error JgHM?AWg|
} `U2DkY&n
wY"Q o7
7.j[a*^
String sHeader; x]z2Z*
t='# |');
;[a|9TPR
for(int i=1;;i++) r7Ya\0gU
{ x"~~l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t!IaUW
//Utility.log(in.readLine()); ] Eh}L
sHeader=httpConnection.getHeaderFieldKey(i); Y6&wJ<
if(sHeader!=null) 1 E22R
{ eAqz3#_My
if(sHeader.equals("Content-Length")) @u1zB:
{ v(pmIb{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h&kZjQ&
break; o-o'z'9
} Wq^qpN)5Y
} E#s)52z=B
else d:F @a
break; A=kH%0s2p@
} ?-Vjha@BO
} 9aJ%`i
catch(IOException e){e.printStackTrace ();} 8iekEG$H
catch(Exception e){e.printStackTrace ();} VM0j`bs'K*
~xoF6CF
77Bgl4P
Utility.log(nFileLength); q7&6r|w1I
R<V!%rL;;
#0Tq=:AE>
return nFileLength; Bphof0{<}
} cm[c ze+*
SRSvot};C
57 #6yXQ
//保存下载信息（文件指针位置） [}fv dW
private void write_nPos() n3sUbs;
{ Q~Z=(rP20
try{ Vrvic4
output = new DataOutputStream(new FileOutputStream(tmpFile)); }cN@[3v
output.writeInt(nStartPos.length); pD&&l!i&[
for(int i=0;i<nStartPos.length;i++) D_8x6`z
{ /6_|]ijc
// output.writeLong(nPos); SvR7eC
output.writeLong(fileSplitterFetch.nStartPos); 5 QO34t2
output.writeLong(fileSplitterFetch.nEndPos); bb d.
} %sRUh0AL
output.close(); N;+[`l
} [{X^c.8G)
catch(IOException e){e.printStackTrace ();} K).n.:vYZ
catch(Exception e){e.printStackTrace ();} )IJQeC
} *FJZiPy
YX*Qd$chZ
OaL\w D^
//读取保存的下载信息（文件指针位置） R-P-i0~
private void read_nPos() K+6e?5t
{ y7^{yS[,
try{ kQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `ImE% r!
int nCount = input.readInt(); 'fL"txW
nStartPos = new long[nCount]; uWrQ&}@
nEndPos = new long[nCount]; XbQlHfrS
for(int i=0;i<nStartPos.length;i++) FW.$5*f='
{ {f{ZHi|
nStartPos = input.readLong(); x=#VX\5k:
nEndPos = input.readLong(); kD}Y|*]5-5
} #A8@CA^d
input.close(); P/`I.p;
} ^#0U ?9
catch(IOException e){e.printStackTrace ();} 7L^%x3-|&
catch(Exception e){e.printStackTrace ();} pc?>cs8
} sp*Vqd
4BwQA#zE
w eQYQrN
private void processErrorCode(int nErrorCode) MJ=)v]a
{ V:G>G'Eh0
System.err.println("Error Code : " + nErrorCode); P<fnLQ9
} >YUoh-]`
rhL"i^
aC<KN:TN6
//停止文件下载 i>_u_)-
public void siteStop() Rml2"9"`
{ RDtU43
bStop = true; y?SyInt
for(int i=0;i<nStartPos.length;i++) nQGQWg`
fileSplitterFetch.splitterStop(); [2|kl l
&[hLzlrg
vp(;W,ba:|
} #b7$TV
} wR{'y)$
//负责部分文件的抓取 =f(cH152T
**FileSplitterFetch.java W14Vm(`N
*/ _`#3f1F@[
package NetFox; 1xc~`~
cv/_r#vN
b}Zd)2G
import java.io.*; ".dZn6"mI
import java.net.*; :eZh'-c?
1bw{q.cmD
b$eXFi/
public class FileSplitterFetch extends Thread { t^ZV|s 1
#Mg]GeDJ{
BYKoel
String sURL; //File URL zB? V_aT
long nStartPos; //File Snippet Start Position V i&*&"q
long nEndPos; //File Snippet End Position ^_ojR4
int nThreadID; //Thread's ID HV/cc"
boolean bDownOver = false; //Downing is over dik9 >*"|o
boolean bStop = false; //Stop identical ` \A(9u*
FileAccessI fileAccessI = null; //File Access interface lHZU iB
^GBe)~MT
,j5&6X=1M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l$hJE;n
{ s[gKc'
this.sURL = sURL; D3c2^r$Z
this.nStartPos = nStart; f7I{WfZ\P
this.nEndPos = nEnd; 5E0eyW
nThreadID = id; ~y$!48o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !`mZ0c+
} F]mgmYD%
#oJ5k8Wy
%AN/>\#p
public void run() r&Ca"dI
{ ?X&6M;Zi
while(nStartPos < nEndPos && !bStop) W>b(Om_%
{ `HuCT6O
eyp,y2Tz
|7KeR-
try{ x3rlJs`$;
URL url = new URL(sURL); )NR Q2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BA=,7y&;j
httpConnection.setRequestProperty("User-Agent","NetFox"); R<x'l=,D(
String sProperty = "bytes="+nStartPos+"-"; e:AHVepj{
httpConnection.setRequestProperty("RANGE",sProperty); {s3z"OV
Utility.log(sProperty); CDi<<,
*UW=Mdt
S60IPya
InputStream input = httpConnection.getInputStream(); ?6!]Nl1gr
//logResponseHead(httpConnection); dSCzx .c
\Ofw8=N-2
MV=9!{`
byte[] b = new byte[1024]; GjB]KA^
int nRead; ?m c%.Bt
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }CxvT`/
{ mQ}ny(K'
nStartPos += fileAccessI.write(b,0,nRead); 0[<~?`:)
//if(nThreadID == 1) 5b/ojr7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Il`tNr
} +wW@'X
U}$DhA"r"
"S&%w8V
Utility.log("Thread " + nThreadID + " is over!"); >]=j'+]
bDownOver = true; na^sBq?\
//nPos = fileAccessI.write (b,0,nRead); MuBx#M/
} "g+z !4b#
catch(Exception e){e.printStackTrace ();} @u._"/K
} t\v+ogbk)
} >5G>D~b
C!C|\$)-
MCh#="L2
//打印回应的头信息 HMY@F_qY`u
public void logResponseHead(HttpURLConnection con) Ol$WpM
{ )~jqW=d 2
for(int i=1;;i++) _IeU+tS
{ 71C42=AU
String header=con.getHeaderFieldKey(i); E|:!Q8"%w
if(header!=null) E0oU$IB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rd3j1U
Utility.log(header+" : "+con.getHeaderField(header)); N-w(e
else iqW1#)3'R
break; $mGvJ*9
} iK{T^vvk
} %PJhy2
ftBq^tC
IaFr&
public void splitterStop() ;W:6{9m ze
{ [@fz1{*
bStop = true; (qwdQMj`
} 7~M<cD
eo^/c+FG
zdSh:
} 0iEa[G3
IF*&%pB
_y .]3JNm
/* woq)\;CK
**FileAccess.java 5.tvB
*//文件访问(定位，写) _{~]/k
package NetFox; `B8tmW#
import java.io.*; nT#JOmv
wcDjg&:=ml
TFDm5XJ
public class FileAccessI implements Serializable{ Kt#,]]
DG;y6#|p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2>em0{e
RandomAccessFile oSavedFile; W4YE~
long nPos; GD-&_6a
/NF#+bx
NN 0Q`r,8}
public FileAccessI() throws IOException .I$}KE)
{ ^;F{)bmu+)
this("",0); )R{UXk3q}
} 7 gB{In0
xn}BB}s{t
*@ED}Mj+
public FileAccessI(String sName,long nPos) throws IOException GbU@BN+_
{ ^+?|Qfi
oSavedFile = new RandomAccessFile(sName,"rw"); !p 8psi0
this.nPos = nPos; ;LJ3c7$@lf
oSavedFile.seek(nPos); t^EhE
} #G3N(wV3
6Gn4asoA
> 7`&0?
public synchronized int write(byte[] b,int nStart,int nLen) f"&Xr!b.h
{ /&ygiH{^
int n = -1; }fhHXGK.
try{ 0'$p$K
oSavedFile.write(b,nStart,nLen); 3}&ZOO
n = nLen; #p yim_
} K'6[J"dB
catch(IOException e) ,ZI\dtl
{ K^%-NyV
e.printStackTrace (); u@FsLHn
} ?)3jqQ.
N~,_`=yRx
>Cd9fJ&0gP
return n; +C7T]&5s
} cQpnEO&SL
MmU%%2QG
Uedvc5><t
} nq`q[KV:
bdc\
:cp
/* [~Hg}-c
**SiteInfoBean.java 0o&}mKe
*/ <xS=#
package NetFox; qg,Nb
=;c_} VY
xQt 3[(Z
public class SiteInfoBean { YRB%:D@u
Fm j=
]@xL=%
private String sSiteURL; //Site's URL |Svk^mq
private String sFilePath; //Saved File's Path _py2kjA6
private String sFileName; //Saved File's Name 0kCQ0xB[a5
private int nSplitter; //Count of Splited Downloading File J+<p+(^*v
T%CxvZ
[5pCL0<c@
public SiteInfoBean() W7G9Kx1Y
{//nSplitter的缺省值为5 zJ& b|L
//default value of nSplitter is 5 >mIg@knE
this("","","",5); DacJ,in_I{
} )@:l^$x
ehO:')XF
zsTbdF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &^ I+s^\=
{ 9F_6}.O
sSiteURL= sURL; +?N}Y{Y&
sFilePath = sPath; Ht=$] Px
sFileName = sName; J^H=i)A
this.nSplitter = nSpiltter; IKf`[_,t]
)bWrd$X
O<,r>b,
} ,@Z_{,b
Rlc$;Z9K
8l xY]UT
public String getSSiteURL() Ob&W_D^=N
{ B/YcSEY;
return sSiteURL; ,8SWe
} ?ei%RWo
>riq98Us/
!7` [i
public void setSSiteURL(String value) /(%Ig,<"JC
{ VJ1*|r,
sSiteURL = value; q`loOm=y
} :Ee?K
],?pe
IrO+5w
public String getSFilePath() M]ap:
{ u:4["ViC
return sFilePath; tyXl}$)y
} dF2@q@\.+
W]LQ &f
_bQL[eXd
public void setSFilePath(String value) ze"~Ird
{ w4OW4J#
sFilePath = value; a@SUi~+3
} 2NR7V*A
=K6c;
ta! V=U
public String getSFileName() <$C<Ba?;?
{ !1-&Y'+
return sFileName; V [4n'LcE
} FU]4oKx
IgA.%}II}
}vsO^4Sjc
public void setSFileName(String value) )H+h;U
{ s-5wbi.C
sFileName = value; RO(iHR3cA
} t,?,F4j
^n71'MW
<UAP~RH{
public int getNSplitter() QE6El'S
{ |B|@GF?:
return nSplitter; pU DO7Q]
} BA`:miH<
UG=I~{L
#L1>dHhat
public void setNSplitter(int nCount) FAd``9kRT
{ zn[QvY
nSplitter = nCount; '8Qw:fh
} !Ud:?U
} E.#6;HHzN
Xv*}1PZH
)[ w&C_>]
/* CSH`pU
**Utility.java 9mm2Vps;
*/ O99mic
package NetFox; x.G"D(
4a 4N C
B<C&ay
public class Utility { /.2u.G
e7's)C>/'
:s-EG;.
public Utility() >@:667i,`
{ %6Rp,M9=
EJ8I[(
z1}1*F"
} B{=009.
<hMtE/05B
//线程睡眠 Z{#"-UG
public static void sleep(int nSecond) NJ>,'s
{ Za9$Hh/X
try{ .o"<N
Thread.sleep(nSecond); @4&, #xo
} p~FQcW'a~
catch(Exception e) edTMl;4
{ i9y3PP)
e.printStackTrace (); a.CF9m5]c
} D8EeZUqU
} O*ImLR)i+s
1M=
//日志 iW;}%$lVX
public static void log(String sMsg) t,1in4sN
{ "kU>~~y,
System.err.println(sMsg); kLq(!Gs
} 'hy?jQ'|e
$wgc vySx
{Wa~}1`Kl
public static void log(int sMsg) psu OJ-
{ d<_NB]V&F
System.err.println(sMsg); jwq\stjD
} S$\.4*_H\
} ;raz6DRO
`i9N)3 X
7|K3WuLL
/* 7}A5u,.,ht
**TestMethod.java Nr%(2[$ =
*/ 0K/G&c?;=
package NetFox; ]L$4Py
Hw y5G;
CJm.K
public class TestMethod { prwC>LE
P3i^S_
"*+\KPCU
public TestMethod() TbMdQbj}
{ ///xx/weblogic60b2_win.exe !5? m
try{ =MCNCV/<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T!1SMo^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); </|)"OD9
SiteFileFetch fileFetch = new SiteFileFetch(bean); YsZ{1W
fileFetch.start(); !e&rVoA
} 2+,5p
catch(Exception e){e.printStackTrace ();} |7]?>-
Yg[ v/[]
0hFH^2%UY
} |.Em_*VG
Z@}sCZ=#A
abL/Y23 "
public static void main(String[] args) FOc|*>aKP
{ 2YE7 23H=Z
new TestMethod(); 3IGCl w(
} B>sCP"/uV
} Sf=F cb
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