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)); ]G:xTv8
} m| Z)h{&
for(int i=0;i<nEndPos.length-1;i++) [C$ 0HW
{ #_d%hr~d
nEndPos = nStartPos[i+1]; @lwqkJ
} a|.u;
nEndPos[nEndPos.length-1] = nFileLength; 'g#GUSXfj
} {% P;O ?
} YdFCYSiS
l_:%?4MA
)7^jq|
//启动子线程 &kG<LGXP#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c\Dv3bF
for(int i=0;i<nStartPos.length;i++) utr_fFu
{ om1 /9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XL:7$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *XJSa
nStartPos,nEndPos,i); rhrlEf@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Uu/1TTf
fileSplitterFetch.start(); |fUSq1//
} DcOLK\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hXCDlCO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D)Zv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DCj!m<Y&
nEndPos = " + nFileLength); b|NEU-oy
// fileSplitterFetch[nPos.length-1].start(); Y3[@(
+ '`RJ,K+[
CVm*Q[5s"
//等待子线程结束 R:Lu)d>=
//int count = 0; 4T:ZEvdzf
//是否结束while循环 4Xz|HU?
boolean breakWhile = false; _#+i;$cO-X
%X3T<3<
D<MtLwH
while(!bStop) &b_duWs
{ "k.<"pf
write_nPos(); fc91D]c
Utility.sleep(500); 6vDgMfw
breakWhile = true; .MKxHM7
Fq8Z:;C8
[(C lvGx
for(int i=0;i<nStartPos.length;i++) y3x_B@}BY
{ M<SZ7^9<
if(!fileSplitterFetch.bDownOver) e*tOXXY1
{ r<U }lK
breakWhile = false; MStaP;|
break; hYLu
} ]?^mb n
} ,q4Y N-3
if(breakWhile) BEw(SQH
break; ?IK[]=!
aa|xZ
C-8@elZ1
//count++; YJ6Xq||_
//if(count>4) <*L8kNykK
// siteStop(); E:2Or~
} NunT1ved
[Mx+t3M
p|zW2L
System.err.println("文件下载结束！"); x`4">:IA
} [8ih-k
catch(Exception e){e.printStackTrace ();} o.,hCg)X
} 8O]$)E
?n}L+|
c5JxKU_
//获得文件长度 BwR)--75
public long getFileSize() IMj{n.y4
{ NOvN8.K%
int nFileLength = -1; .A E(D7d6
try{ Yv>% 5`
URL url = new URL(siteInfoBean.getSSiteURL()); [,VD^\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |g~.]2az
httpConnection.setRequestProperty("User-Agent","NetFox"); nk[ixVc
Ra/S46$
Ta_#Rg*!
int responseCode=httpConnection.getResponseCode(); T!8,R{V]4
if(responseCode>=400) sPut@4[S
{ z;T?2~g!
processErrorCode(responseCode); Gd!y,n&s
return -2; //-2 represent access is error 9BP-Iet
} -{HA+YL H
[l0>pHl@
OmsNo0OA
String sHeader; FbF P
(f7R~le
qTG/7tn "
for(int i=1;;i++) \j4TDCs_[
{ sq_ f[!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OF}vY0oiw?
//Utility.log(in.readLine()); z&w@67 >j
sHeader=httpConnection.getHeaderFieldKey(i); LKhUqW
if(sHeader!=null) y:mXv<g
{ V V<Zl
if(sHeader.equals("Content-Length")) flRok?iF
{ Gx!Y 4Q}-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o<Q~pd#Ip,
break; >mz<=n
} HZ/e^"cpM
} KrB"2e+J
else Bx)4BPaN
break; opd^|xx0
} ~OXPn9qPp
} "~XAD(T6
catch(IOException e){e.printStackTrace ();} }}<^fM
catch(Exception e){e.printStackTrace ();} s$A|>TOY
+ps(9O/B>
J%{>I
Utility.log(nFileLength); /@:I\&{f'9
(m13 ong
`j9 ;9^
return nFileLength; DKR2b`J
} Yf1?3(0O
nPE{Gp) }
T< D&%)
//保存下载信息（文件指针位置） ta%yQd7
private void write_nPos() G@s rQum(
{ `#R[x7bA1
try{ 09/Mg
output = new DataOutputStream(new FileOutputStream(tmpFile)); `KB;3L
output.writeInt(nStartPos.length); 6YNd;,it>p
for(int i=0;i<nStartPos.length;i++) L\aG.\
{ voiWf?X
// output.writeLong(nPos); 5y0N }}
output.writeLong(fileSplitterFetch.nStartPos); wZ0RI{)s'
output.writeLong(fileSplitterFetch.nEndPos); X3@Uih}|
} `fS$@{YI_
output.close(); ]@0C1r
} Kqm2TMO]>V
catch(IOException e){e.printStackTrace ();} y2KR^/LN|Y
catch(Exception e){e.printStackTrace ();} @kd`9Yw
} :>f}rq
/@ m]@
A{MMY{K3
//读取保存的下载信息（文件指针位置） z#m ~}
private void read_nPos() \(C6|-:GY
{ Qu|H_<8g
try{ K|]/BjB/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s+DOr$\
int nCount = input.readInt(); 508v:?^'
nStartPos = new long[nCount]; <- L}N '
nEndPos = new long[nCount]; g=n{G@*N
for(int i=0;i<nStartPos.length;i++) ^M0
{ ]jjHIFX
nStartPos = input.readLong(); f3^Anaa]l
nEndPos = input.readLong(); *PM#ngLX}r
} }]<0!q &xB
input.close(); 4 Fl>XM
} ]Q$Sei5
catch(IOException e){e.printStackTrace ();} }p5_JXBV
catch(Exception e){e.printStackTrace ();} Kl_(4kQE_
} )Vd^#p
$t0o*i{
f\xmv|8
private void processErrorCode(int nErrorCode) iSbPOC7
{ ||D PIn]
System.err.println("Error Code : " + nErrorCode); !y+uQ_IS@
} x n?$@
4( $p8J
*+(rQ";x
//停止文件下载 %tB7 &%ut
public void siteStop() R#HVrzOO|T
{ ^p)#;$6b
bStop = true; OYSq)!:
for(int i=0;i<nStartPos.length;i++) 'hR0JXy
fileSplitterFetch.splitterStop(); 5\V""fH
KT[ZOtu
agt/;>q\~
} Hsn'"
} z^vfha
//负责部分文件的抓取 qA0PGo
**FileSplitterFetch.java # ~Doz7~
*/ sKCYGt$
package NetFox; hi`[
DG?g~{Y~b
t'1g+g
import java.io.*; pu~b\&^G
import java.net.*; ,oykOda:|
X!_&%^L'
e>6|# d
public class FileSplitterFetch extends Thread { DL`8qJ'mJs
{7jl) x3l
X$e*s\4
String sURL; //File URL By waD?
long nStartPos; //File Snippet Start Position {xx}xib3
long nEndPos; //File Snippet End Position )xq=V
int nThreadID; //Thread's ID v*[UG^+)
boolean bDownOver = false; //Downing is over .' }jd#
boolean bStop = false; //Stop identical O uNPDq%
FileAccessI fileAccessI = null; //File Access interface Z_[ P7P
9U8x&Z]P
,Qx]_gZ`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `Fie'[F5,)
{ zOd*>
this.sURL = sURL; w"5Eyz-eO
this.nStartPos = nStart; vJxEF&X
this.nEndPos = nEnd; UB/"&I uo
nThreadID = id; h4jo<yp\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .fbY2b([
} :s6aFiz
A 0v=7 ]
;plBo%EBV
public void run() To}eJ$8*5
{ Q 9fK)j1$
while(nStartPos < nEndPos && !bStop) EB| iW2'
{ ((C|&$@M
/{f"0]-RA
Qo)Da}uo20
try{ 9dq"x[
URL url = new URL(sURL); 6@TU9AZS`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A|GtF3:G
httpConnection.setRequestProperty("User-Agent","NetFox"); 8tQ;N'
String sProperty = "bytes="+nStartPos+"-"; TG[u3Y4
httpConnection.setRequestProperty("RANGE",sProperty); -'Ay(h
Utility.log(sProperty); qCg<g
2TUV9Z
(>vyWd]
InputStream input = httpConnection.getInputStream(); O 2-n-
//logResponseHead(httpConnection); fGb}V'x}r
udu<Nis4
{.542}A
byte[] b = new byte[1024]; m^!:n$
int nRead; 4j~q,#$LW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =WjHf8v;
{ :`e#I/,
nStartPos += fileAccessI.write(b,0,nRead); V1B!5N<
//if(nThreadID == 1) 0KnL{Cj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ("\{=XAQ
} 5CZyA`3V^5
vP x/&x
L/Q[N^ (^
Utility.log("Thread " + nThreadID + " is over!"); o!:Z?.!
bDownOver = true; `Jk0jj6Z
//nPos = fileAccessI.write (b,0,nRead); VxBBZsZO~
} ;+<IWDo
catch(Exception e){e.printStackTrace ();} jB(+9?;1${
} A+="0{P
} ''YqxJ fb
g]lEG>y1R
p;>A:i
//打印回应的头信息 YZ5,K6u
public void logResponseHead(HttpURLConnection con) `mzlOB
{ W?5')
for(int i=1;;i++) Ux7LN@4og
{ R|n
String header=con.getHeaderFieldKey(i); gYhY1Mym
if(header!=null) 9T;4aP>6j#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <mQXS87
Utility.log(header+" : "+con.getHeaderField(header)); LP6p
else l3sF/zkH
break; SK lvZ
} wkM1tKhy/
} /QY F|%7!
iqvLu{
q0NFz mG
public void splitterStop() W}f)VC;D
{ }:m/@LKB
bStop = true; ux<|8S
} o5bp~.m<
8 MQq3
)GkJ%o#H2
} T9 /;$6s*
f^FFn32u
7pm'b,J<
/* m,lZy#02s3
**FileAccess.java &]DB-t#\
*//文件访问(定位，写) ?qNU*d
package NetFox; -N8rs[c
import java.io.*; x="Wqcnj{
`Gqe]ZE#"
pcy;]U?
public class FileAccessI implements Serializable{ <{isWEW9]3
jc&k-d>=G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !&{rnK
RandomAccessFile oSavedFile; au{)5W4~
long nPos; 5dm~yQN/
SXk.7bMV6
o]4]fLQ
public FileAccessI() throws IOException itg_+%^R
{ j(=w4Sd_W
this("",0); 5tYo! f
} (-gomn
_#u\ar)
f' ?/P~[
public FileAccessI(String sName,long nPos) throws IOException A`n>9|R
{ n9'3~qVZ
oSavedFile = new RandomAccessFile(sName,"rw"); a_RY Yj
this.nPos = nPos; riDb!oC
oSavedFile.seek(nPos); 17 Ugz?
} wXKtQ#o}
hq 3n&/
=]%JTGdp(
public synchronized int write(byte[] b,int nStart,int nLen) vN Bg&m
{ 0~bUW V
int n = -1; Wef%f]u
try{ pR61bl)
oSavedFile.write(b,nStart,nLen); wtw=RA
n = nLen; <E2 IU~e
} e$Ksn_wEq
catch(IOException e) BS9VwG<Z
{ w\)K0RN
e.printStackTrace (); 3YHEH\60^
} h3o'T=`Sm
suY47DCX)
1,-C*T}nR
return n; ye(b 7CX
} l~i?
&DLWlMGq
dHy9 wU
} wXIRn?z
B*Tn@t W
jH< #)R
/* 1&|]8=pG7
**SiteInfoBean.java 2? qC8eC
*/ z`wIb
package NetFox; l7|z]v-
fz(YP=@ZnP
#EH=tJgO|J
public class SiteInfoBean { ;|q<t
C?\(?%B
\O5L#dc#
private String sSiteURL; //Site's URL 9{u=
private String sFilePath; //Saved File's Path F7DA~G!
private String sFileName; //Saved File's Name =I# pXL
private int nSplitter; //Count of Splited Downloading File YnEyL2SuU
'H530Y\
I0m7;M7 P
public SiteInfoBean() Gyq 6?
{//nSplitter的缺省值为5 ?()*"+N(ck
//default value of nSplitter is 5 hY`<J]-'`
this("","","",5); ]3LLlXtK[
} 5T x4u%g
q`9.@u@a
^&qK\m_A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,b*?7R
{ CD&a_-'z$K
sSiteURL= sURL; |p:4s"NT
sFilePath = sPath; bf_ >?F^
sFileName = sName; $e\s8$EO
this.nSplitter = nSpiltter; bo\ bs1
Uu_qy(4
vNSUrf,r
} \D@j`o
Z[#8F&QV!m
2R\K!e
public String getSSiteURL() 5i[O\@]5
{ /HdXJL9B
return sSiteURL; 1dN/H)]
} V'kBF2}
@Tu`0=8
T8S&9BM7
public void setSSiteURL(String value) L1SX2F8
{ ~O}r<PQ
sSiteURL = value; D_l$"35?
} 2j-l<!s
A%^?z.
ctP+ECH
public String getSFilePath() vFUp$[
{ k-~}KlP
return sFilePath; {8m&Z36E
} Qw0k-t0=4
Cff6EE
*y4DK6OFe
public void setSFilePath(String value) xm{?h,U,
{ P.Ntjz/B
sFilePath = value; 5gf ~/Zr
} sl$6Zv-l%0
^(q .f=I!a
QD-\'Bp/X
public String getSFileName() mnA_$W3~I
{ S)EF&S(TC
return sFileName; <V^o.4mOg>
} sVh)Ofn
I#OZ:g^
%Xc,l Y1?
public void setSFileName(String value) 2hHRitt36
{ I bD u+~)
sFileName = value; L(3&,!@
} "]eB2k_>
T6/P54S
q]4h#?.-1v
public int getNSplitter() XJo.^<m
{ KpGx<+0p
return nSplitter; ;-3&yQ7N)
} o33t~@RX
w[GEm,ZC
CbZ;gjgY*
public void setNSplitter(int nCount) vAM1|,U
{ lf-.c$.>
nSplitter = nCount; kwp%5C-S
} 'd N1~Pa
} ozY$}|sjDT
H^'%$F?Ss
G&h@
/* F:jNv3W1
**Utility.java _n:RA)4*
*/ >a975R*g
package NetFox; 2D:/.9= 8v
_OGv2r
3FvVM0l"
public class Utility { Fx!D:.)/G
^x0N]/
6|=]i-8
public Utility() Tv#d>ZSD
{ l$5nv5r
]EK(k7nH
,hf W2}
} ViW2q"4=
]U#of O
//线程睡眠 )"?'~5A
public static void sleep(int nSecond) @KM?agtlbl
{ f I%8@ :
try{ B*:I-5
Thread.sleep(nSecond); Z,p@toj'
} d%I7OBBx@
catch(Exception e) o~'p&f
{ ^Zvb3RJg
e.printStackTrace (); a=W%x{
} '`;=d<'
} Z'A 3\f
qMEd R;o
//日志 dA~_[x:Z
public static void log(String sMsg) u"zR_CzYc
{ %KVmpWku
System.err.println(sMsg); ]-t>F
} b~UWFX#U
sPc}hG+N
vw>(JCR
public static void log(int sMsg) ktPM66`b
{ z4 =OR@ h
System.err.println(sMsg); }J?,?>Z
} >-V632(/{o
} z 8M\(<
E-^(VZ_Xj
9Tr ceL;
/* Ytc[ kp
**TestMethod.java 48z%dBmTT*
*/ o6^ETQ
package NetFox; TfJ*G6\7e#
3XB`|\:
t;Z9p7rk
public class TestMethod { +wz1kPRs
7:g_:}m
4Y'Ne2M{
public TestMethod() #8L:.,AYE
{ ///xx/weblogic60b2_win.exe khjdTq\\
try{ ]i075bO/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &KBDrJEX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5mV!mn:H:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8a)4>B
fileFetch.start(); 9_==C"F
} 1?w=v|b:P)
catch(Exception e){e.printStackTrace ();} !4<D^eh
^O<v'\!z-
`oe=K{aX
} dLGHbeZ[(
'DXT7|Df
h<M1q1)
public static void main(String[] args) t]Ln(r
{ 1.u^shc&|
new TestMethod(); UUDbOxD^w
} #qk=R7"Q
} /":/DwI'
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