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)); Z-|.j^n
} |S.G#za
for(int i=0;i<nEndPos.length-1;i++) I^"ouM9}Q
{ /aS=vjs
nEndPos = nStartPos[i+1]; D\|$!i}
} m=D2|WA8
nEndPos[nEndPos.length-1] = nFileLength; yO*~)ALb+
} -4ry)isYx
} mM&Sq;JJ;
[8|Y2Z\N
@_s`@,=
//启动子线程 Ie{98
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qt`hUyL
for(int i=0;i<nStartPos.length;i++) /jl{~R#1
{ ]&6# {I-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HS>(y2}'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xIu#
nStartPos,nEndPos,i); Py*( %
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M)S(:Il6Xx
fileSplitterFetch.start(); z~&uLu
} -^sW{s0Rc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m(CW3:|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j1{|3#5V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d 90
nEndPos = " + nFileLength); gGF]Dq
// fileSplitterFetch[nPos.length-1].start(); p3>(ZWPNV
)_bc:6Q
TNe,'S,%
//等待子线程结束 ZrY#B8
//int count = 0; p}q27<O*/
//是否结束while循环 $ N`V%<W
boolean breakWhile = false; 9U[Gh97Sf
|dIP &9
zVN/|[KP4
while(!bStop) GL;@heP
{ 3ARvSz@5
write_nPos(); Gk_%WY*
Utility.sleep(500); Z]?Tx2|7
breakWhile = true; N(i%Oxp1
q#LB 2M
>[t0a"
for(int i=0;i<nStartPos.length;i++) ^u'hl$`^
{ "XPBNv\>_
if(!fileSplitterFetch.bDownOver) $VEG1]/svp
{ _|<kKfd?
breakWhile = false; l-s%3E3
break; cs[_TJo
} EWOS6Yg7
} p7 s#j
if(breakWhile) >tF3|:\
break; 'Cv,:Q
]0N'Wtbn
aD)$aK
//count++; !ieMhJ5r
//if(count>4) oh*Hzb
// siteStop(); n>Cl;cN=
} wq yw#)S
@ig'CF%(
x_za R}WI
System.err.println("文件下载结束！"); rJLn=|uR
} 3V=(P.ATm
catch(Exception e){e.printStackTrace ();} aq~>$CHa
} -s~6FrKy
y?=W
$ti*I;)h4
//获得文件长度 '{]1!yMh
public long getFileSize() E/bIq}R6
{ vW6 a=j8
int nFileLength = -1; 5cc;8i
try{ lMkDLobos
URL url = new URL(siteInfoBean.getSSiteURL()); .CJQ]ECl7p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xae0xs
httpConnection.setRequestProperty("User-Agent","NetFox"); d)@Hx8
'ec G:B`S
(!b_o A8V
int responseCode=httpConnection.getResponseCode(); E :gS*tsY
if(responseCode>=400) w+A:]SU
{ Skb,cKU
processErrorCode(responseCode); 0e./yPTT
return -2; //-2 represent access is error 'XW[uK]w)
} >?Y)evW
lT.Q)(
&d,chb(
String sHeader; \9;SOAv
_N`'R.va
zk6al$3R
for(int i=1;;i++) RYhaQ&1i
{ )"( ojh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8aDSRfv*
//Utility.log(in.readLine()); ,m4M39MWJ
sHeader=httpConnection.getHeaderFieldKey(i); JA]TO(x
if(sHeader!=null) 0!4;."S
{ G.j R
if(sHeader.equals("Content-Length")) '5^$v{
{ g/*x;d=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m(2(Caz{
break; "n<rP 3y
} 7JC^+rk
} c}XuzgSY
else )q.Z}_,)@
break; ^O>G?a
} Th!.=S{Y5
} T6/d[SH>
catch(IOException e){e.printStackTrace ();} ! z!lQ~
catch(Exception e){e.printStackTrace ();} Y!3Mm*
3k%fY
Qu 7#^%=
Utility.log(nFileLength); )gX7qQ
z@70{*
4}i2j
return nFileLength; 3K{XT),
} A%Ov.~&\G
=J@M,mbHg
r'TxYM-R
//保存下载信息（文件指针位置） [_$r-FA
private void write_nPos() :eK(9o
{ Vgh;w-a
try{ Z)JJ-V!
output = new DataOutputStream(new FileOutputStream(tmpFile)); |AosZeO_
output.writeInt(nStartPos.length); ~Onj|w7
for(int i=0;i<nStartPos.length;i++) N3M:|D
{ N+)gYb6h
// output.writeLong(nPos); ]YQ!i@Y
output.writeLong(fileSplitterFetch.nStartPos); f+}Rj0A
output.writeLong(fileSplitterFetch.nEndPos); /5x~3~
} }kNbqwVP
output.close(); ]mfI$p%
} <V> [H7
catch(IOException e){e.printStackTrace ();} rwZI;t$hf
catch(Exception e){e.printStackTrace ();} tQ:g#EqL9B
} KBUClx?
C(=$0FIR
h;q=<[h\
//读取保存的下载信息（文件指针位置） m=saUhI*9
private void read_nPos() ">{Ruv}$
{ 4jWzYuI&J
try{ s=[Tm}[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B #[URZ9S
int nCount = input.readInt(); ~RdD6V
nStartPos = new long[nCount]; '7'*+sgi$
nEndPos = new long[nCount]; Mz?xvP?z
for(int i=0;i<nStartPos.length;i++) fG *1A\t]
{ \vH /bL
nStartPos = input.readLong(); G<F+/Oi&DX
nEndPos = input.readLong(); Gky e
} EnM }H9A
input.close(); 9S<87sO
} FJ/>=2^B
catch(IOException e){e.printStackTrace ();} 9+z5$
catch(Exception e){e.printStackTrace ();} RFsd/K;Zp
} [RAzKzC\M
%VV\biO]
rNi]|)-ET
private void processErrorCode(int nErrorCode) $ 8"we
{ t:NYsL
System.err.println("Error Code : " + nErrorCode); tQ,,krw~
} (31ia"i%
c `[,>
V6c>1nZ
//停止文件下载 a{4Wg:
public void siteStop() 1v<,nABuJ6
{ @yGK$<R
bStop = true; AZj`o
for(int i=0;i<nStartPos.length;i++) d9j+==S <
fileSplitterFetch.splitterStop(); /w!!jj^
8fG$><@
bqo+b{i\
} O#}d!}SIp
} b]-~{' +
//负责部分文件的抓取 F!>92H~3G
**FileSplitterFetch.java gI~4A,
*/ G}2DZ=&>'
package NetFox; 5B|&+7dCw
(0wQ [(
?{)sdJe
import java.io.*; i 4}4U
import java.net.*; WxLmzSz{xD
RJYB=y8l
>5O#_?
public class FileSplitterFetch extends Thread { zeC@!,lH
Z(|@C(IL0\
\Zn%r&(
String sURL; //File URL a/4!zT
long nStartPos; //File Snippet Start Position uVSc1MS1
long nEndPos; //File Snippet End Position Bql5=p
int nThreadID; //Thread's ID ]j4Nl?5*x
boolean bDownOver = false; //Downing is over K)D5%?D
boolean bStop = false; //Stop identical _mEW]9Sp
FileAccessI fileAccessI = null; //File Access interface 6~oo.6bA
z1K}] z%
a>05Yxw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException : \{>+!`w
{ =7e|e6
this.sURL = sURL; q7z;bA
this.nStartPos = nStart; .wdWs tQ
this.nEndPos = nEnd; !nm[ZrSP
nThreadID = id; 5W Z9z-6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !,SGKLs.m
} Q;V*M
p{V_}:|=Q
71RG1,
public void run() Y:x,pPyl
{ x)]_]_vX
while(nStartPos < nEndPos && !bStop) ytmFe!
{ ym]12PAU5
5PcN$r"P
MV(Sb:RZ
try{ fwN'5ep
URL url = new URL(sURL); 6Mh;ld@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F2N)|C<
httpConnection.setRequestProperty("User-Agent","NetFox"); F0D7+-9[
String sProperty = "bytes="+nStartPos+"-"; J{69iQ
httpConnection.setRequestProperty("RANGE",sProperty); Yn~N;VUA
Utility.log(sProperty); [|vE*&:uO
y^iju(
LH@xr\^
InputStream input = httpConnection.getInputStream(); Z$X[x7e.
//logResponseHead(httpConnection); x;w^&<hQ\
G*`H2-,
K> rZJ[a
byte[] b = new byte[1024]; P3W<a4 ==
int nRead; ^zfO=XN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l%f&vOcd
{ ].!^BYNht
nStartPos += fileAccessI.write(b,0,nRead); ytDp 4x<W)
//if(nThreadID == 1) 76} a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `R\nw)xq
} Miw*L;u@W
+=N!37+G
ask76 e
Utility.log("Thread " + nThreadID + " is over!"); 5PRS|R7
bDownOver = true; NCXr$ES{
//nPos = fileAccessI.write (b,0,nRead); 2w7PwNb*32
} DHnO ,"
catch(Exception e){e.printStackTrace ();} ^&Exa6=*FT
} 6-+q3#e
} NDqvt$
C4].egVg
"44A#0)B'l
//打印回应的头信息 NI%&Xhn!*>
public void logResponseHead(HttpURLConnection con) hoOT]Bsn
{ M'gL_Xsei
for(int i=1;;i++) T, z80m}
{ 5gg Yg$
String header=con.getHeaderFieldKey(i); b@>MA
if(header!=null) 'G#T 6B!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); drM@6$k
Utility.log(header+" : "+con.getHeaderField(header)); {\P`-'C
else k0/S&e,*
break; \-h%z%{R
} MT3TWWtZ:
} f6*6*=
HtN!Hgpwg
-aV!ZODt
public void splitterStop() A><q-`bw
{ l$\OSG
bStop = true; P{gGvC,
} c97?+Y^
T`7HQf ;
U?[_ d
} p_g#iH!*
[#3*R_#8R
Rt6(y #dF
/* \I[f@D-J
**FileAccess.java Osk'zFiL<
*//文件访问(定位，写) WxrGoo^
package NetFox; g2|qGfl{C
import java.io.*; kgl7l?|O
&| guPZ
Pc:5*H
public class FileAccessI implements Serializable{ )<+t#5"
d OYEl<!J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ->rr4xaKC
RandomAccessFile oSavedFile; t!285J8tn
long nPos; kgZiyPcw
YPU*T&~
N+3]C9 2o
public FileAccessI() throws IOException 4owM;y
{ #86=[*Dr
this("",0); >Hd0l L
} >%?kp[
dU"ca|u
iu$:_W_
public FileAccessI(String sName,long nPos) throws IOException |ler\"Eu
{ !Y95e'f.x
oSavedFile = new RandomAccessFile(sName,"rw"); @L/p
this.nPos = nPos; brpsZU
oSavedFile.seek(nPos); ;&2f{
} &$V&gAN
;J&p17~T9
#=81`u
public synchronized int write(byte[] b,int nStart,int nLen) ]aDU*tk
{ ?\.DG`Zxc
int n = -1; D00v"yp%%
try{ K K_
oSavedFile.write(b,nStart,nLen); %0MvCm
n = nLen; G oHdhne3
} +k<0:Fi
catch(IOException e) ^fq^s T.$
{ v{44`tR
e.printStackTrace (); AW')*{/(Ii
} Ui43&B
{S6:LsFfm
*]#(?W.$w
return n; }Tz<fd/
} ^8q(_#w`K
qPvWb1H:
2vLV1v$,q
} L8WYxJ k
4F=cER6l
/qwl;_Jcf
/* 9[@K4&
**SiteInfoBean.java OciPd/6
*/ oa;vLX$
package NetFox; AS-%I+ A
62D UF
g[%^OT#
public class SiteInfoBean { u$%;03hJ
S@^o=B]]
Wq"5-U;:w
private String sSiteURL; //Site's URL YA:!ULzR*
private String sFilePath; //Saved File's Path \nbGdka
private String sFileName; //Saved File's Name "+sl(A3`U
private int nSplitter; //Count of Splited Downloading File A(84cmq!q
`ttqgv\
{Yc#XP
public SiteInfoBean() tMDJ,rT
{//nSplitter的缺省值为5 6!T9VL\=H
//default value of nSplitter is 5 /YrBnccqD
this("","","",5); q?0&&"T}
} =&,<Co1hF
+aoenUm5
eR|u']Em>T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5fjL
{ ;QS(`SK l
sSiteURL= sURL; CxbGL
sFilePath = sPath; G}V5PEF]`
sFileName = sName; L}hc|(:
this.nSplitter = nSpiltter; Gzw9E.Hk
^/M-*U8ab
@ i*It Hk
} F[5sFkM7
j#rj_uP
x;@wtd*QB
public String getSSiteURL() !l|fzS8g
{ *u ^mf~
return sSiteURL; y3Qb2l
} ggL^*MV
'?O_(%3F0
D3(rD]c0{
public void setSSiteURL(String value) 3`+Bq+
{ N% !TFQf
sSiteURL = value; #]5A|-O^
} YW7Pimks
I ]HP
*/)O8`}2
public String getSFilePath() T)lkT?
{ {7Qj+e^
return sFilePath; =~P)7D6
} rInZd`\
VtYrU>q
$i9</Es P
public void setSFilePath(String value) es!>u{8)
{ X6-;vnlKN
sFilePath = value; ESyb34T`
} bB+ 4
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qx f8f
public String getSFileName() VXP@)\!
{ r>_40+|&
return sFileName; "STd ;vR
} cUj^aTpm
svRYdInBNu
C-tkYP
public void setSFileName(String value) i38`2
{ +[B@83
sFileName = value; (,I9|
} p?V@P6h
W!o|0u!D
3k# h!Z
public int getNSplitter() Xx?~%o6
{ Msst:}QY
return nSplitter; t b>At*tO
} FI8vABq
5#U=x ,7e
k{C03=xk
public void setNSplitter(int nCount) zFm:=,9
{ " 7g\X$
nSplitter = nCount; 1)t*l;.
} C0gO^A.d
} "L&84^lmf
)s|o&aP>
V{C{y5
/* g@|2z
**Utility.java %X**(
*/ r) g:-[Ox9
package NetFox; FSD~Q&9&
C17$qdV/
4vJg"*?
public class Utility { C+%6N@
PrhGp _5
_^@>I8ix
public Utility() ["WWaCcx
{ U28frRa
"_ H9]}Q
T!X`"rI
} +!cibTQTT
1b,MJ~g$
//线程睡眠 w&x$RP
public static void sleep(int nSecond) NCivh&HR
{ dZ|x `bIgs
try{ $&X-ay o
Thread.sleep(nSecond); qGdoRrp0Ov
} $ww0$
catch(Exception e) ;[B-!F>
{ '0<9+A#
e.printStackTrace (); Sf'uKSX1%
} D}~uxw;[^
} !W/"Z!k
^4Tf6Fw#
//日志 k!py*noy
public static void log(String sMsg) a: 2ezxP
{ _6.Y3+7I
System.err.println(sMsg); |_mN:(3
} Jd28/X5&
w5`EJp8MC
B^@X1EE
public static void log(int sMsg) Slv91c&md,
{ UsgrI>|l
System.err.println(sMsg); TjS&V
} 3(`P x}
} rGlnu.mK^
n;LjKE
a FL;E
/* H,EGB8E2
**TestMethod.java PZihC
*/ \Vx_$E
package NetFox; t!\B6!Fo
wwE3N[
?N=`}}Ky-
public class TestMethod { ;r}yeISf
sBa&]9>m
|4rqj1*U
public TestMethod() .l$U:d
{ ///xx/weblogic60b2_win.exe O>d [;Q
try{ sAS[wcOQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o>HU4O}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O=}d:yZb!
SiteFileFetch fileFetch = new SiteFileFetch(bean); Sq]QRI/
fileFetch.start(); L&0aS:
} NUFW SL>
catch(Exception e){e.printStackTrace ();} _&N}.y)+t
rV}&G!V_t
v8K`cijSS
} .Bojb~zt
1 %8JMq\
3F32 /_`
public static void main(String[] args) OMAvJzK .
{ $r)NL
new TestMethod(); n(W&GSj|u9
} [l}H%S
} x/0loW?q^
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