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)); _Y7:!-n}
} x:C@)CAr
for(int i=0;i<nEndPos.length-1;i++) !OQuEJR
{ Loc8eToZ
nEndPos = nStartPos[i+1]; +I.v!P!^
} @SQceQfB
nEndPos[nEndPos.length-1] = nFileLength; R_9 o!sTZ
} =SL^>HS.fo
} LT&/0
JilKZQmk
Re\o v x9
//启动子线程 }6@%((9E2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hG~Uz
for(int i=0;i<nStartPos.length;i++) +WdL
{ (-'PD_|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D9G0k[D,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 85Dm8~
nStartPos,nEndPos,i); 'F<Sf:?.p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5E.vje{U;
fileSplitterFetch.start(); U5clQiow
} No~6s.H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ty2_6&>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X$PS(_M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Lqm#]C
nEndPos = " + nFileLength); _]_LF[
// fileSplitterFetch[nPos.length-1].start(); 'Dq"e$JM<
O E]~@eU
ME,duY/>Q
//等待子线程结束 8ur_/h7
//int count = 0; uAQg"j
//是否结束while循环 3m~U(yho
boolean breakWhile = false; (Y>U6
X;5S
vS2(Q0+TZi
while(!bStop) r=|vad$
{ lkyJ;}_**
write_nPos(); Y& m<lnB
Utility.sleep(500); fW[_+r]
breakWhile = true; ?Cc$]
.;j"+Ef
y "<JE<X
for(int i=0;i<nStartPos.length;i++) }Uq/kei^P
{ #W.bZ]&WA
if(!fileSplitterFetch.bDownOver) ;wpW2%&
{ R<t&F\>
breakWhile = false; )biX8yqhR
break; |B,dEx/uU
} WE7>?H*Ro
} JfR kp
if(breakWhile) Zq9>VqGe
break; 9/^d~ZO
we @Yw6<
y.%i
//count++; cx<h_
//if(count>4) vDWr|M%``l
// siteStop(); EyzY2>"^
} x9TuweG
cFe V?a
YqkA&qL]#;
System.err.println("文件下载结束！"); @RQ+JYQi
} .!9Vt#
catch(Exception e){e.printStackTrace ();} "hz>{oe
} i^~sn `o
5NFq7&rJ6
e-1;dX HL
//获得文件长度 n2H&t>N
public long getFileSize() t% <pbZO
{ 5BZ+b_A>VV
int nFileLength = -1; _8Pmv$
try{ yFIl^Ck%
URL url = new URL(siteInfoBean.getSSiteURL()); JHHb|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EC0zH#N
httpConnection.setRequestProperty("User-Agent","NetFox"); n&3iz05}
e3G7K8
.`b4h"g:
int responseCode=httpConnection.getResponseCode(); q=J9LQ
if(responseCode>=400) T %$2k>
{ @^BS#
processErrorCode(responseCode); $HP/cKu
return -2; //-2 represent access is error 5^bh.uF
} <d3PDO@w/
4,o %e,z
`e4o1*
String sHeader; !>?4[|?n<
JvT%R`i
N;e}dwh&
for(int i=1;;i++) !^n1
{ xq8}6Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U;^CU!a
//Utility.log(in.readLine()); x;<oaT$X
sHeader=httpConnection.getHeaderFieldKey(i); <|ka{=T
if(sHeader!=null) I3V{"Nx6
{ c8H9_6
if(sHeader.equals("Content-Length")) 2(@LRl>:
{ nYmf(DV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mrw]yu;2<n
break; 8') .ohD
} };4pZceV
} \H},ouU
else B4PW4>GF
break; g/fp45s
} ly9x1`?$
} m T>b;
catch(IOException e){e.printStackTrace ();} #JHy[!4
catch(Exception e){e.printStackTrace ();} (jD'+ "?
zZS>+O
J r=REa0
Utility.log(nFileLength); oHv{Y
<L[T'ZE+
liBAJx
return nFileLength; HQ ELK
} BT y]!%r'
v4nvZ6
0(Yh~{
//保存下载信息（文件指针位置） Nv}U/$$S
private void write_nPos() )*q7pO\cty
{ V'Sd[*
try{ T)$6H}[c
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z1XUYe62
output.writeInt(nStartPos.length); R!:eYoQ
for(int i=0;i<nStartPos.length;i++) LC~CPV'F
{ tuL\7 (R
// output.writeLong(nPos); G~b`O20N
output.writeLong(fileSplitterFetch.nStartPos); bW,BhUb,|
output.writeLong(fileSplitterFetch.nEndPos); E#IiyZ
} ?uNTUU,
output.close(); 4i ~eTb
} xg*\j)_}
catch(IOException e){e.printStackTrace ();} ~z-?rW
catch(Exception e){e.printStackTrace ();} v Ie=wf~D`
} __oY:d(~
-N /8Ho
}.fZy&_
//读取保存的下载信息（文件指针位置） "t3uW6&
private void read_nPos() N2+mN0k;
{ D;16}D
try{ ,)B~cic'u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SXT@& @E
int nCount = input.readInt(); UBUB/NY
nStartPos = new long[nCount]; (Von;U
nEndPos = new long[nCount]; W>aQ tT
for(int i=0;i<nStartPos.length;i++) wsdB; 6%$
{ e>ZbZy?
nStartPos = input.readLong(); \FY/eQ*07
nEndPos = input.readLong(); yhw:xg_;Kz
} \UkNE5
input.close(); k'WS"<-
} 6Y92&
catch(IOException e){e.printStackTrace ();} |ec(z
catch(Exception e){e.printStackTrace ();} k8Su/U
} JO<gN= [
mM\!4Yi`7
u`L!za7fi
private void processErrorCode(int nErrorCode) |g: '')>[
{ &UJTy'
System.err.println("Error Code : " + nErrorCode); &k%wOz1vM
} mTrI""Jsu;
.>AFf9P
(IO\+
//停止文件下载 LXTipWKz
public void siteStop() ZYl-p]\*y
{ 6I5[^fv45G
bStop = true; )Ta]6
for(int i=0;i<nStartPos.length;i++) ^-csi
fileSplitterFetch.splitterStop(); /:*R -VdF
W_e-7=6
"W,"qFx
} @vQ;>4i.
} wt_?B_nR
//负责部分文件的抓取 nkr,
**FileSplitterFetch.java 1A)wbH)
*/ kcma/d
package NetFox; >ji}j~cH
6bA~mC^&
b6?Xo/lJ.
import java.io.*; eJVOVPg<,
import java.net.*; Z7KB?1{G
SoM ]2^
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public class FileSplitterFetch extends Thread { rH}Dt@
3LmBV\["
n'x`oI)-
String sURL; //File URL XSHwE)m
long nStartPos; //File Snippet Start Position lhIr]'?l
long nEndPos; //File Snippet End Position c!(~BH3p
int nThreadID; //Thread's ID {8>_,z^P)
boolean bDownOver = false; //Downing is over U#FJ8CD&u
boolean bStop = false; //Stop identical LzEE]i
FileAccessI fileAccessI = null; //File Access interface fO^EMy\
.eDxIWW+ft
mXN1b!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6"rFfdns
{ yoQ?lh
this.sURL = sURL; wZ\e3H z
this.nStartPos = nStart; n_!]B_Vd$
this.nEndPos = nEnd; }ii]cY
nThreadID = id; [w#x5Xsn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &s6(3k
} :+Z>nHe
=Y=^]ayO/
46.q anh
public void run() [<3Q$*Ew
{ EiIFVP
while(nStartPos < nEndPos && !bStop) %8`1Li6g
{ 0F;(_2V-
t6,M
m?kIa!GM=
try{ 7Hr4yh[j&
URL url = new URL(sURL); Jz:W-o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gYH:EuY,
httpConnection.setRequestProperty("User-Agent","NetFox"); vI:bl~
String sProperty = "bytes="+nStartPos+"-"; ,{mf+ 3&$,
httpConnection.setRequestProperty("RANGE",sProperty); 5sV/N] !
Utility.log(sProperty); ][>M<J
&|&YRHv
?`[ uh%
InputStream input = httpConnection.getInputStream(); o`y*yucHI
//logResponseHead(httpConnection); >FMT#x t
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5)SZd)
byte[] b = new byte[1024]; '\E*W!R.]
int nRead; 2YP"nj#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @T~#Gwv
{ WY.\<$7
nStartPos += fileAccessI.write(b,0,nRead); l.NkS
//if(nThreadID == 1) |2t7mat
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nD?M;XN
} $0`$)(Y
X-2S*L'
*IO;`k q,;
Utility.log("Thread " + nThreadID + " is over!"); k @/SeE
bDownOver = true; Wp9 2sm+
//nPos = fileAccessI.write (b,0,nRead); .5Z@5g`
} 3vGaT4TDx
catch(Exception e){e.printStackTrace ();} da86Jj=k
} EA@$^e[
} %H 6ZfEO
`))J8j"
KlX |PQ
//打印回应的头信息 u>i+R"hi"
public void logResponseHead(HttpURLConnection con) H|Fqc=qp
{ u4*]jt;H
for(int i=1;;i++) ]2sZu7
{ jiB>.te
String header=con.getHeaderFieldKey(i); {HJ`%xN|
if(header!=null) 3b[[2x_UU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {pJ@I=q
Utility.log(header+" : "+con.getHeaderField(header)); Y|N vBr
else I9j+x])
break; fM[fS?W
} kKk |@
} &u`rE""
nR|LV'(
'hHX"\|RA
public void splitterStop() 2Q_{2(nQb
{ GHsdLe=t0#
bStop = true; !vo'8r?&
} ][K8\
&8YI)G%
U@t?jTMBkO
} VEYKrZA
uB&I56
SIBIh-L
/* BHBT=,sI
**FileAccess.java lo;9sTUHT
*//文件访问(定位，写) .$s|T
package NetFox; nF y7gA|
import java.io.*; xbH!:R;
$8ww]}K
iqKfMoy5
public class FileAccessI implements Serializable{ Wes"t}[25
ZYt"=\_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DBrzw+;e3
RandomAccessFile oSavedFile; &l}xBQAL
long nPos; S$_Ts1Ge6
-clg'Aa;.
N*)8L[7_;
public FileAccessI() throws IOException \]:NOmI^'
{ ghd[G}
this("",0); j tkPi)QR
} K.L+; nQ
f%%En5e+
Q_h+r!b
public FileAccessI(String sName,long nPos) throws IOException (=/L#Yg_
{ ScmzbDu
oSavedFile = new RandomAccessFile(sName,"rw"); yW,#&>]# |
this.nPos = nPos; gl{PLLe[}
oSavedFile.seek(nPos); +q?0A^C>
} P##(V!YR
2o3k=hKS
~ilBw:L-3
public synchronized int write(byte[] b,int nStart,int nLen) .?)oiPW#
{ <+JFal
int n = -1; 0J,d9a [1
try{ G/;aZ
oSavedFile.write(b,nStart,nLen); Jt^JE{m9%
n = nLen; .xQ'^P_q
} M@ZpgAfq
catch(IOException e) <T~fh>a
{ RpXGgw
e.printStackTrace (); &XTd[_VW!
} EC\:uK
gK_[3FiKt
b6M)qt9R
return n; mztq7[&-
} 3\~fe/z'I
>bP7}T
a_MnQ@
} QF6JZQh<
"JGig!9
+GtGyp
/* ^7<mlr
**SiteInfoBean.java &y wY?ox
*/ gM[ J'DMW
package NetFox; g5N<B+?!i
(w
,colGth54
public class SiteInfoBean { KvOI)"0(
f;dU72]q+
H LGy"P
private String sSiteURL; //Site's URL P[K T
private String sFilePath; //Saved File's Path *J5euA5=
private String sFileName; //Saved File's Name "r3s'\
private int nSplitter; //Count of Splited Downloading File 7n]%`Yb
iz5wUyeg
m|gd9m$,?
public SiteInfoBean() RLX^'g+P
{//nSplitter的缺省值为5 ;XuEMq,Di
//default value of nSplitter is 5 n,LKkOG
this("","","",5); ]KT,s].
} [:'?}p
\`5u@Nzx
J~`%Nj5>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $F$R4?_
{ UeeV+xU
sSiteURL= sURL; }r<^]Q*&p
sFilePath = sPath; [,X,2
sFileName = sName; `;GGuJb \
this.nSplitter = nSpiltter; dR{ V,H7N
6MQ:C'8T&=
QP0X8%+p
} HaUo+,=
5ml}TSMu'
n:] 1^wX#
public String getSSiteURL() =x]dP.
{ rs+37
return sSiteURL; 1D DOUV
} 8Y'"=!3
{-qTU6
k= 1+mG
public void setSSiteURL(String value) L#bQ`t
{ ay[*b_f
sSiteURL = value; M&-/&>n!
} "A3xX&9-q
l_EI7mJ
A2S9h,t
public String getSFilePath() S*:w\nXP~
{ vH8%a8V
return sFilePath; ]iX$p~riH
} Rj=Om
_@76eZd
j)*nE./3
public void setSFilePath(String value) 5nb6k,+E
{ bd}SB-D
sFilePath = value; pSUp"wch
} ZK*aVYnu
y$NG..S
4tTJE<y
public String getSFileName() z|H>jit+
{ NQ=YTRU
return sFileName; Dw,f~D$+ic
} kJFHUR
c>.Xc[H
Lcm!e
public void setSFileName(String value) BT0hx!Ti
{ Gjr2]t;E
sFileName = value; !~v>&bCG>9
} (P8oXb+%
&i RX-)^u
r U5'hK
public int getNSplitter() \ }f*
{ xc?<:h"
return nSplitter; rfpxE>_|G
} E3.s8}}
2_v>8B
:"]ei@
public void setNSplitter(int nCount) LcF3P 4
{ :LG%8Z{R
nSplitter = nCount; A4h/oMis
} h65j,v6B
} rg.if"o
H)tDfk sq\
F{tSfKy2
/* L~~Yh{<
**Utility.java cw{[B%vw
*/ Y?cw9uYB
package NetFox; |&vuK9q
o5R40["
U)8]pUI+/P
public class Utility { <X*8Xzmv
37Y]sJrs$
_#B/#^a
public Utility() eH{ 9w8~
{ 6Tnzg`0I
]9Hy "#Fz
Nig-D>OS
} F)Lbr>H?I
sd%~pY}
//线程睡眠 7/L7L5h<
public static void sleep(int nSecond) *_wBV M=2
{ :_*Q IyW
try{ w3D_ c~
Thread.sleep(nSecond); pkx>6(Y
} vKf=t&gqr
catch(Exception e) g=Di2j{A
{ -f=hL7NW
e.printStackTrace (); $(U|JR@
} 9j`-fs@:
} mZyTo/\0
wQT'~'kL
//日志 6*7&X#gG
public static void log(String sMsg) _L":Wux
{ bSfQH4F
System.err.println(sMsg); HenJlo
} ~@lNBF
F04Etf 2k
R8l9i2
public static void log(int sMsg) xJCpWU3wM
{ )w-?|2-w5
System.err.println(sMsg); CCV~nf
} Rd)QVEk>SD
} UZ#2*PH2E
d/1XL[&
s9iM hCu|
/* \BL9}5y
**TestMethod.java @#apOoVW>
*/ Sls> OIc
package NetFox; /Ny&;Y
5oS\uX|
o6 /?WR9
public class TestMethod { Cmj)CJ-
q@:&^CS
"|if<hx+
public TestMethod() 3nO|A: t
{ ///xx/weblogic60b2_win.exe n>WS@b/o
try{ XJ;/kR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 00i9yC8@6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N2>JG]G
SiteFileFetch fileFetch = new SiteFileFetch(bean); bb{+
fileFetch.start(); 8{C3ijR
} Tx*m p+q
catch(Exception e){e.printStackTrace ();} fvDwg
*M:Bhw
DN+`Q{KS
} Ju<D7
9!LAAE`
jJ|;Nwm<[
public static void main(String[] args) ^;a[v^&9
{ y.zQ `
new TestMethod(); J}JnJV8|G
} c,@6MeKHq
} v,;?+Ck
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