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)); $`{}4,5M
} B&-;w_K
for(int i=0;i<nEndPos.length-1;i++) Vn=J$Uv0
{ 4y>G6TD^
nEndPos = nStartPos[i+1]; o~mY,7@a
} |Ro\2uSr
nEndPos[nEndPos.length-1] = nFileLength; ~ Z%>N
} `S;pn+5
} }9 qsPn
CSt6}_c!
}eEF/o
//启动子线程 +:/`&LOS-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XfViLBY( >
for(int i=0;i<nStartPos.length;i++) 5C#&vYnq
{ FRs5 Pb1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6CY_8/:zL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \<T6+3p
nStartPos,nEndPos,i); ;,Lq*x2s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B7?784{x,
fileSplitterFetch.start(); k}F;e_
} "W\ #d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N<$uAns
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W5J"#^kdF8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #V4_.t#
nEndPos = " + nFileLength); Vi5RkUY]
// fileSplitterFetch[nPos.length-1].start(); zVl(?b&CF
${6 ;]ye
k3S**&i!CR
//等待子线程结束 \-V
//int count = 0; m"H9C-Y
//是否结束while循环 XImb"7|
boolean breakWhile = false; Q?W]g%:)
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o#%2N+w
while(!bStop) %S$P+B?
{ rIS \#j
write_nPos(); %z.u % %
Utility.sleep(500); ,((5|MbM/
breakWhile = true; ;<ed1%Le,
?B@iBOcu[
6M612
for(int i=0;i<nStartPos.length;i++) g>VkQos5"
{ R:^GNra;
if(!fileSplitterFetch.bDownOver) (doFYF~w
{ cJi5\<b
breakWhile = false; RX7,z.9@'O
break; G^)|c<'M
} el+euOV
} \$riwL
if(breakWhile) 0($MN]oZa
break; =_.Zv
W!GgtQw{F
E*rDwTd
//count++; iFS?nZ~.
//if(count>4) ^[^uDE <
// siteStop(); h'IBVI!P
} >MiA|N=
r95$B6
G}}oeS
System.err.println("文件下载结束！"); bLaD1rnGi
} ^t9"!K
catch(Exception e){e.printStackTrace ();} F4">go
} X$PT-~!a
8.]dThaq
B6$s*SXNp
//获得文件长度 @f{)]I +f
public long getFileSize() b>I -4
{ =We}&80x
int nFileLength = -1; :^J(%zy
try{ LDwu?"P!
URL url = new URL(siteInfoBean.getSSiteURL()); 63-`3R?;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a/`fJY6rR
httpConnection.setRequestProperty("User-Agent","NetFox"); +,c;Dff
7m@pdq5Ub
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int responseCode=httpConnection.getResponseCode(); s~M!yuH
if(responseCode>=400) qXP)R/~OZ
{ -D{~7&
processErrorCode(responseCode); q'q'v S
return -2; //-2 represent access is error |MTgKEsn
} Y:*mAv;&
M(?|$$
FW[<;$
String sHeader; Oh<Z0M)
t(Iy[-
2ORWdR.b
for(int i=1;;i++) G0y%_"[
{ $0iz;!w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )p12SGR5
//Utility.log(in.readLine()); 1pO ;aG1O
sHeader=httpConnection.getHeaderFieldKey(i); r`wL_>"{n
if(sHeader!=null) klJDYFX=HK
{ LF*3Iw|v
if(sHeader.equals("Content-Length")) 3)42EM'9(
{ ?aO%\<b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i!YZF$|
break; vAwFPqu
} OdwSNG
} J6NQ5S\
else D95$
break; Fk=_Q LI
} ^D oJ='&
} Pgye{{
catch(IOException e){e.printStackTrace ();} .B#Lt,m
catch(Exception e){e.printStackTrace ();} ]p+t>'s
6TPcG dZ
rw_&t>Ri;
Utility.log(nFileLength); _[XEL+.
Z''Fz(qMC
gtjgC0
return nFileLength; [h8F)
} bp$8hUNYz-
Q 7B)t;^
%k$+t
//保存下载信息（文件指针位置） >[ 72]<6
private void write_nPos() ]~kqPw<R
{ [.dNX
try{ )-9|3`
output = new DataOutputStream(new FileOutputStream(tmpFile)); NF&\<2kX
output.writeInt(nStartPos.length); R&PQ[Xc
for(int i=0;i<nStartPos.length;i++) 0#Rj[J;kh
{ ,EwJg69
// output.writeLong(nPos); pklcRrx,a
output.writeLong(fileSplitterFetch.nStartPos); Ie4*#N_
output.writeLong(fileSplitterFetch.nEndPos); @$+l ^"#-]
} '*-X3p
output.close(); HT1bsY 0t
} *p.ELI1IC
catch(IOException e){e.printStackTrace ();} =Eef
catch(Exception e){e.printStackTrace ();} 2(`2f
} `yuD/-j
]e?*7T]
m{+lG*
//读取保存的下载信息（文件指针位置） IwWo-WN7.
private void read_nPos() (7Y :3
{ z:<(b
try{ c%uhQ62
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G*J(4~Yw}
int nCount = input.readInt(); pLyX9C
nStartPos = new long[nCount]; |G%MiYd
nEndPos = new long[nCount]; mYt(`S*q
for(int i=0;i<nStartPos.length;i++) Hyee#fB
{ (W@ ypK@
nStartPos = input.readLong(); b[RBp0]x
nEndPos = input.readLong(); f<kL}B+,Og
} Z$WT ~V
input.close(); ;?n*w+6<
} LGod"8~U
catch(IOException e){e.printStackTrace ();} {MYlW0)~
catch(Exception e){e.printStackTrace ();} 4S"K%2'O
} n]8_]0{qi
M6DyOe<
o_\b{<^I
private void processErrorCode(int nErrorCode) ?pQ, 5+8
{ Jw {:1
System.err.println("Error Code : " + nErrorCode); {v]>sn;P1
} sBSBDjk[
P<2yCovn`
1N#TL"lMS
//停止文件下载 5l)p5Bb48c
public void siteStop() iZ_R oJ
{ ) mv}u~
bStop = true; K90Zf
for(int i=0;i<nStartPos.length;i++) Bpk%,*$*)
fileSplitterFetch.splitterStop(); ""WZpaw
*=;=VUu5
@)}Vk
} d,D)>Y'h
} RKBjrSZg8
//负责部分文件的抓取 cwpDad[Kx
**FileSplitterFetch.java L<Lu;KnY6
*/ }3?M0:
package NetFox; X.UIFcK^
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Tmw :w~
import java.io.*; GXHk{G@TS
import java.net.*; 1/#N{rZ
z*9/"M
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public class FileSplitterFetch extends Thread { ~CM{?{z;
h+*
(.n" J2qj
String sURL; //File URL W tzV|e,
long nStartPos; //File Snippet Start Position Fg,[=CqB[
long nEndPos; //File Snippet End Position z1V0WDVm
int nThreadID; //Thread's ID wh~~g qi9
boolean bDownOver = false; //Downing is over *`l>1)B>
boolean bStop = false; //Stop identical 5T8!5EcS*
FileAccessI fileAccessI = null; //File Access interface 8^4X/n
ec]ksw6T+
h_A}i2/{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G&Cl:CtC
{ 1":{$A?OB
this.sURL = sURL; oW/&X5
this.nStartPos = nStart; B8TI 5mZ4
this.nEndPos = nEnd; Qy3e,9nS
nThreadID = id; kYR&t}jlCg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4&$G;?#W2
} "3hw]`a}
#lB[]2]N
`__CL )N|
public void run() ' !_44
{ 0{B5C[PTG
while(nStartPos < nEndPos && !bStop) <R!qOQI
{ tDi=T]-bt
+h9CcBd
Cu|n?Uk
try{ NGxii$F
URL url = new URL(sURL); 1DLQZq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -l,ib=ne
httpConnection.setRequestProperty("User-Agent","NetFox"); }& 1_gn15
String sProperty = "bytes="+nStartPos+"-"; bMv9f J
httpConnection.setRequestProperty("RANGE",sProperty); Az)P&*2:'`
Utility.log(sProperty); z_Qw's
r^\^*FD |
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InputStream input = httpConnection.getInputStream(); Y@r#:BH)
//logResponseHead(httpConnection); m|-O/6~
?`w ~1
E?FPxs
byte[] b = new byte[1024]; .z{7 rH
int nRead; ^iI^)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UIu'x_qc
{ !c*^:0
nStartPos += fileAccessI.write(b,0,nRead); Y&j6;2-Z
//if(nThreadID == 1) ;nC+Kz:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v h%\ " h
} c/hml4
=LT({8
I5bi^!i
Utility.log("Thread " + nThreadID + " is over!"); P,v}Au( UI
bDownOver = true; B@s\>QMm
//nPos = fileAccessI.write (b,0,nRead); [@\f 0R
} C&;'Pw9H
catch(Exception e){e.printStackTrace ();} NuP@eeF>,
} ;=n7 Z
} k5ZwGJ#r
(Ux%7H_d
F`ihw[ Wn
//打印回应的头信息 K]7@%cS
public void logResponseHead(HttpURLConnection con) j"NqNv
{ .&[nS<~`
for(int i=1;;i++) ioviJ7N% O
{ JTb<uC
String header=con.getHeaderFieldKey(i); \J13rL{<
if(header!=null) |FcG$[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :7`,dyIqT
Utility.log(header+" : "+con.getHeaderField(header)); PD$'xY|1=
else SOUA,4
break; UGN. ]#"#
} pH*L8tT
} 1/{:}9Z@
Ny~;"n
-~aVt~{k/
public void splitterStop() `Y[zF1$kz^
{ t]vz+VQ
bStop = true; |_ @iaLE
} @ J"1!`
r*3;gyG.,#
6-JnT_
} x x 'XR'zK
3!}#@<j
BPPhVE
/* 'WOWm$2
**FileAccess.java I%(+tJ
*//文件访问(定位，写) Qv?jo(]
package NetFox; r!zNcN(%cs
import java.io.*; /!9949XV
#uH1!UQb
*;}!WDr
public class FileAccessI implements Serializable{ "Fke(?X'
T0SD|'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JRNyvG>j
RandomAccessFile oSavedFile; [mwfgh&4%
long nPos; F>}).qx
`Yut1N
Im Tq`
public FileAccessI() throws IOException :wF(([&4p!
{ %] Bb;0G
this("",0); Bq_<v)M*
} Npu;f>g0_
:l7\7IT
[OT@gp:
public FileAccessI(String sName,long nPos) throws IOException d82IEhZ#
{ ({8Q=Gh
oSavedFile = new RandomAccessFile(sName,"rw"); 7i'vAOnw^
this.nPos = nPos; s$]I@;_
oSavedFile.seek(nPos); {6KU.'#iF
} \/,SH?>4x
N-NwGD{
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public synchronized int write(byte[] b,int nStart,int nLen) &B3kzs
{ !k[zUti
int n = -1; z1"UF4x*
try{ [Y:HVr,
oSavedFile.write(b,nStart,nLen); $4L=Dg
n = nLen; "zv+|_ZAfd
} {1qEN_ERx
catch(IOException e) BY 1~\M
{ ``O\'{o&
e.printStackTrace (); HPgMVp'
} ~L1N1Z)Kk
:<jf}[w!
jRBx7|ON
return n; QzS{2Y[OQ
} 8m9G^s`[
3;Xs`dk
JlH|=nIaj6
} N*z<VZ
5Q^~Z},
@emZwN"m
/* TS%cTh'ItH
**SiteInfoBean.java w%$n)7<*
*/ Le}q>>o;q
package NetFox; O_:Q#
bM!`C|,[s
}M1<a4~
public class SiteInfoBean { Q/+a{m0f
Xau.4&\d
pu^1s#g8w
private String sSiteURL; //Site's URL )dvOg'it
private String sFilePath; //Saved File's Path C=Zuy^
private String sFileName; //Saved File's Name _}\&;
private int nSplitter; //Count of Splited Downloading File g)"6|Z?D"
qaQ
AfY(+w6!K
public SiteInfoBean() Sj*H4ZHD<&
{//nSplitter的缺省值为5 -Wig k['v
//default value of nSplitter is 5 wgufk{:
this("","","",5); 'z\F-Ttq
} Vt&I[osC
I?:V EN:
w8on3f;6n#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zZy>XHR H
{ ~q9RZ#g13J
sSiteURL= sURL; 2<'gX>TW
sFilePath = sPath; ' ZB%McS
sFileName = sName; ZWFH5#=
this.nSplitter = nSpiltter; Ne4A
n1LS*-@
D?E5p.!A
} MRa>@Jn??A
a( qw
z4<h)hh"k6
public String getSSiteURL() 6-^+btl)#
{ O=mJ8W@
return sSiteURL; /q^( uWu
} ;Rt,"W)
dzcPSbbpt
LO2sP"9
public void setSSiteURL(String value) ,p2 Di
{ [m"X*ZF
sSiteURL = value; $pD^O!I)?
} leiza?[
;CC[>
`aUA_"f
public String getSFilePath() fL@[B{XMM
{ bySw#h_
return sFilePath; Gh< r_O~L3
} )PwDP
-}>Q0d)
CR_A{(
public void setSFilePath(String value) QTDI^ZeuF
{ KSexG:Xb
sFilePath = value; I7}[%(~Sf/
} ](O!6_'d
7_|zMk.J*
QM$?}>:
public String getSFileName() TcqqAc
{ w,P2_xk`
return sFileName; ZA# jw 8F
} >Qi2;t~G
E0*81PS
U2h?l `nP
public void setSFileName(String value) >yaz
{ <?I~ +
sFileName = value; J4JKAv~3
} L-Hl.UV
EBn7waBS
m=#2u4H4
public int getNSplitter() .|rpj&>g
{ BeVQ[
return nSplitter; -dza_{&+iZ
} 8L&#<Ol
{? 6]_J
{% ;tN`{M
public void setNSplitter(int nCount) $V@IRBm
{ u6D>^qF}@'
nSplitter = nCount; +4@EJRC
} =XqmFr;h
} (llg!1
fghJj@ES
-ERDWY
/* C^uXJ~8
**Utility.java $cYh X^YG.
*/ p^^<BjkQ
package NetFox; f>Ij:b`Z2
`i<U;?=0'
aiz_6@Qfz*
public class Utility { zEa3a
G"C'/
%SIbpk%
public Utility() p6sXftk
{ 1YQ|KJ*K
Id9hC<8$dq
l.FkX
} 7=}`"7i~
8*lVO2
//线程睡眠 [ibnI2I]`
public static void sleep(int nSecond) c!j$-Ovm
{ A5z5e# ,u
try{ 1*#64Y5F
Thread.sleep(nSecond); Z}WMpp^r
} 6=iz@C7r
catch(Exception e) <AzvVSA,
{ <kp?*xV]]
e.printStackTrace (); LG@5Z-
} 6 fL=2a
} =M>pL+#
C#+Gkzq
//日志 *i&ks>4N
public static void log(String sMsg) >q"mI6F
{ }H\wed]F/
System.err.println(sMsg); /0@'8f\I
} ,d$V-~2,
R>yoMk/u
;3 O0O
public static void log(int sMsg) KHI-m9(
{ x}{/) ?vC
System.err.println(sMsg); EH=[!iW;
} :!n_a*.{
} j!F5gP-l
gQ6_]~4
2h%/exeS;
/* zT 9"B
**TestMethod.java krFuEaO
*/ % tTL
package NetFox; 9'Le}`Gf
Uf4A9$R.G
p D-k<8|
public class TestMethod { ;p)RMRMg
EyO=M~nsS
bbCH(fYbu
public TestMethod() aA7}>
{ ///xx/weblogic60b2_win.exe zmB6Y t
try{ ^ ~'&K e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #ueWU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o<cg9
SiteFileFetch fileFetch = new SiteFileFetch(bean); {<+B>6^
fileFetch.start(); mSdByT+dG
} _3~/Z{z8
catch(Exception e){e.printStackTrace ();} <n? cRk'.
K2|2Ks_CS
G9v'a&
} ZRHK?wg'#
>}?jOB
Pu>jECcz
public static void main(String[] args) wz`\RHL
{ -Y>,\VEK
new TestMethod(); 1K{u>T
} Jui:Ms
} KTtB!4by
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