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)); M6mJ'Q482
} G&?,L:^t
for(int i=0;i<nEndPos.length-1;i++) 1p%75VW
{ S.$/uDwo
nEndPos = nStartPos[i+1]; ,%uK^U.zk
} 6_#:LFke
nEndPos[nEndPos.length-1] = nFileLength; >I^_kBa
} +LEU|#
} )t#v55M
%l.5c Sn@
BA 9c-Ay
//启动子线程 s;[OR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o8A1cb4<T
for(int i=0;i<nStartPos.length;i++) F=qG+T
{ v.~uJ.T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u}:p@j}Zv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )^^Eh=Kbj
nStartPos,nEndPos,i); lz-t+LD@ST
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8M DX()Bm
fileSplitterFetch.start(); >Y\$9W=t
} ^ rB7&96C,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D')m8:>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i4XE26B;e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $0OWPC1
nEndPos = " + nFileLength); -3)]IA
// fileSplitterFetch[nPos.length-1].start(); jZ5 mpYUO
# {'1\@q
8>KBh)q
//等待子线程结束 2 u{"R
//int count = 0; y`n'>F11
//是否结束while循环 IB sQaxt.
boolean breakWhile = false; 0';U3:=i,
-hpJL\ng
7Y?=ijXXx\
while(!bStop) #w *]`5 T
{ s:fy *6=[Z
write_nPos(); m/`"~@}&
Utility.sleep(500); V:wx@9m)
breakWhile = true; =mq02C~y
s?JNc4q
iLyJ7zby
for(int i=0;i<nStartPos.length;i++) ,vnHEY&
{ X9YYUnR2
if(!fileSplitterFetch.bDownOver) Y5Ub[o
{ uzA_Zjx
breakWhile = false; jYv`kt
break; (1|_Nr
} O$2'$44HX
} QQB\$[M!Z
if(breakWhile) /;[Zw8K7
break; :JEzfI1
n'&Cr0{
n&`=.[+A
//count++; Rqk;!N
//if(count>4) h5x_Vjj
// siteStop(); "i}?jf {a
} POl[]ni=>
o!";&\,Ip
Do3g^RD#
System.err.println("文件下载结束！"); CflGj0oy8
} ?0U.1N
catch(Exception e){e.printStackTrace ();} ^hpdre"
} EEU)eltI
"wB~*,Ny
G<S(P@ss
//获得文件长度 ~BSIp .
public long getFileSize() Gs2|#*6
{ y(#Aze{yC
int nFileLength = -1; &at^~o
try{ F@76V$U.
URL url = new URL(siteInfoBean.getSSiteURL()); 7B|ddi7Q>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u; c)Tt
httpConnection.setRequestProperty("User-Agent","NetFox"); K!JXsdHK
] BJ]
L=ala1{O
int responseCode=httpConnection.getResponseCode(); lf<?k
if(responseCode>=400) SnK#YQCDt
{ ?gp:uxq,.
processErrorCode(responseCode); "M)kV5v%
return -2; //-2 represent access is error 7_HJ|QB
} ) r8yt}
(iwZs:k-
IfK%i/J
String sHeader; sS 5aJ}Qs
yo#aX^v~y
~HW}Wik
for(int i=1;;i++) IfeCSK,x
{ qmWK8}F.cE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D*Cn!v$
//Utility.log(in.readLine()); D4@'C4kL
sHeader=httpConnection.getHeaderFieldKey(i); 8f\sG:$
if(sHeader!=null) :sf(=Y.qA
{ {0&'XA=j
if(sHeader.equals("Content-Length")) n<}t\<LG^c
{ d".Xp4}f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [&tN(K9*
break; *J ]2"~_.
} #J=@} S)
} nB;yS<
else t_VF=B^LuR
break; ]M:=\h,t>
} p41TSALq
} \:'|4D]'I
catch(IOException e){e.printStackTrace ();} %ut^ O
catch(Exception e){e.printStackTrace ();} 0R#T3K}
o7qZy |\4S
u?ALZxj?
Utility.log(nFileLength); l8$7N=Y
I6q]bQ="
<~rf;2LZ
return nFileLength; ._6|epJ#
} x#-+//
-Um|:[*I
4v=NmO}
//保存下载信息（文件指针位置） 7sC8|+
private void write_nPos() i*T>,z
{ NoR=:Q 9e
try{ jt*VD>ji
output = new DataOutputStream(new FileOutputStream(tmpFile)); &!adW@y
output.writeInt(nStartPos.length); q=_&izmE'7
for(int i=0;i<nStartPos.length;i++) B9Ha6kj
{ ^:(:P9h
// output.writeLong(nPos); Ah_Ttj
output.writeLong(fileSplitterFetch.nStartPos); 6v]y\+
output.writeLong(fileSplitterFetch.nEndPos); "TLY:V
} S7I8BS[*v
output.close(); viLK\>>
} |X'Pa9u
catch(IOException e){e.printStackTrace ();} >h[ {_+
catch(Exception e){e.printStackTrace ();} *Dz<Pi^
} k=7+JI"J
8|*=p4_fn
M_ GN3
//读取保存的下载信息（文件指针位置） f19~B[a
private void read_nPos() KBb{Z;%
{ aCwb[7N
try{ Y!+q3`-%T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p5`d@y\hj
int nCount = input.readInt(); bR0z$~
nStartPos = new long[nCount]; Zl:Z31
nEndPos = new long[nCount]; jgkJF[t`
for(int i=0;i<nStartPos.length;i++) Xyf7sHQ
{ ^EG@tB $<
nStartPos = input.readLong(); oD0N<Ln}
nEndPos = input.readLong(); NY& |:F
} 1Ar6hA
input.close(); k *#fN(_
} +pq/:h
catch(IOException e){e.printStackTrace ();} V*|#j0}b
catch(Exception e){e.printStackTrace ();} '/h~O@Rw
} 9T#JlV
M<sY_<z
(ohza<X;6
private void processErrorCode(int nErrorCode) M[Kk43;QY!
{ dWCUZ,6}
System.err.println("Error Code : " + nErrorCode); TsX(=N_
} 5z$>M3
9qqzCMrI0e
gA&+<SK(
//停止文件下载 ]Q%|69H}B
public void siteStop() IO(Y_7
{ q,W6wM;,E
bStop = true; LMV0:\>
for(int i=0;i<nStartPos.length;i++) RCS91[
fileSplitterFetch.splitterStop(); Ke_&dgsq
W/U_:^[-
TC2gl[
} sbZ^BFqp
} o*L#S1yL
//负责部分文件的抓取 p PF]&:&-b
**FileSplitterFetch.java iTt#%Fs)4M
*/ !Gphs`YI
package NetFox; rQ4i%.
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Rj/9\F3H
import java.io.*; .q>4?+
import java.net.*; Od>^yhn
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public class FileSplitterFetch extends Thread { iz2I4 _N
UacGq,
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String sURL; //File URL Lnk!zj
long nStartPos; //File Snippet Start Position `f@VX :aL}
long nEndPos; //File Snippet End Position lZ3o3"
int nThreadID; //Thread's ID NjTVinz
boolean bDownOver = false; //Downing is over .CrrjS w
boolean bStop = false; //Stop identical ~N i#xa
FileAccessI fileAccessI = null; //File Access interface a=55bEn
A/ eZ!"Y
[N|/d#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a?+Ni|+
{ [7gyF}*;
this.sURL = sURL; ,tEvz
this.nStartPos = nStart; CIM9~:\
this.nEndPos = nEnd; /nK)esB1L
nThreadID = id; q4k)E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n0X_m@
} ^6?NYHMr=
<JA`e+Bi
=5P_xQx
public void run() M y:9
{ /!o(Y8e>x
while(nStartPos < nEndPos && !bStop) eJMD8#
{ \ B~9Ue!
{__Z\D2I
&`a$n2ycy
try{ LE_1H>
URL url = new URL(sURL); ~P*t_cpZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &gkGH<oaX
httpConnection.setRequestProperty("User-Agent","NetFox"); 9T47U; _)
String sProperty = "bytes="+nStartPos+"-"; \?,'i/c-
httpConnection.setRequestProperty("RANGE",sProperty); IJ^KYho
Utility.log(sProperty); .+G),P)
v+Vpak9|
]P TTI\n
InputStream input = httpConnection.getInputStream(); '676\2.
//logResponseHead(httpConnection); #e.2m5T
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byte[] b = new byte[1024]; %/dYSC
int nRead; j%iz>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a1p:~;f}[
{ M/5e4b
nStartPos += fileAccessI.write(b,0,nRead); UA[2R1}d
//if(nThreadID == 1) d:0RDK-}s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =R#K`H66j
} pmyHto"
9&}`.Py
pb`F_->uq
Utility.log("Thread " + nThreadID + " is over!"); yhe$A<Rl=
bDownOver = true; m?-3j65z
//nPos = fileAccessI.write (b,0,nRead); rE"`q1b#
} =:aH2T*
catch(Exception e){e.printStackTrace ();} 9Ot;R?>(
} Nt#zr]Fz
} sk!v!^\_r
u~yJFIo
59";{"sw
//打印回应的头信息 \)VV6'zih
public void logResponseHead(HttpURLConnection con) o)KF+[^
{ BQv+9(:fQB
for(int i=1;;i++) vV1F|
{ 9Y1&SEsNX
String header=con.getHeaderFieldKey(i); 0U]wEz*b
if(header!=null) 3ik
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Vb06z3"r
Utility.log(header+" : "+con.getHeaderField(header)); \t'(&taX<
else w!)B\l^+c
break; !*.mcIQT
} s bd;Kn
} -UkP{x)S
^jb55X}
} ab@Nd$
public void splitterStop() EvIL[\Dy
{ o:_}=1nh
bStop = true; 0Fsz
} XJsHy_6
qSj2=dlW
A] pLq`
} JpE4 o2
H r?G_L
jdQ`Y+BC
/* n'0^l?V
**FileAccess.java *7.!"rb8A
*//文件访问(定位，写) T5NO}bz
package NetFox; OwV>`BIwns
import java.io.*; p*F&G=ZE
>|!F.W
ed4:r/Dpo
public class FileAccessI implements Serializable{ 0/S|P1!b
]K0<DO9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G!k&'{2
RandomAccessFile oSavedFile; Lv+lLK
long nPos; vL@N21u
Hv(0<k6oH
[Rw0']i`4
public FileAccessI() throws IOException !!4_x
{ Oga0CR_
this("",0); z:bxnM2\
} 2]5dSXD
6ND,4'6
aB"W6[
public FileAccessI(String sName,long nPos) throws IOException z+FhWze
{ h<\o[n7j
oSavedFile = new RandomAccessFile(sName,"rw"); -X5rGp++
this.nPos = nPos; m `~/]QQ
oSavedFile.seek(nPos); ChF:N0w? p
} bwUsE U 0
!OekN,6
)`yxJ;O@$
public synchronized int write(byte[] b,int nStart,int nLen) o!^':mll
{ #>GUfhou)
int n = -1; |1X^@
try{ pL8+gL
oSavedFile.write(b,nStart,nLen); u&?J+
n = nLen; bVSa}&*kM
} Lw\ANku
catch(IOException e) .]0B=w* Z
{ /lkIbmV
e.printStackTrace (); tiSN amvG1
} sh[Yu
+b1(sk=4z
q0{KYWOvk
return n; Ke,UwYG2~G
} sy+1xnz
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Y*;Z(W.V#
} hNmC(saMGm
zM"OateA
Fx2 KRxk
/* Gp'rN}i^
**SiteInfoBean.java zg+78
*/ ?Q[uIQ?dV
package NetFox; {ER! 0w/
]?S\So+
xu(5U`K
public class SiteInfoBean { ))|Wm}
^;@q^b)ZP
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private String sSiteURL; //Site's URL @'j=oTT
private String sFilePath; //Saved File's Path 5:/ zbt\C
private String sFileName; //Saved File's Name U:m[* }+<
private int nSplitter; //Count of Splited Downloading File o0^..f
rlk0t159
QCQku\GLV
public SiteInfoBean() W!8g.r4u+,
{//nSplitter的缺省值为5 w'z?1M(*
//default value of nSplitter is 5 Er^ijh,
this("","","",5); }tv%
} 9%WUh-|'p
#Mw|h^Wm
zOD5a=[1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (m80isl
{ \.y|=Ql_u
sSiteURL= sURL; LHU^%;L
sFilePath = sPath; h 92\1,
sFileName = sName; 5A/8G}'XZ
this.nSplitter = nSpiltter; IXNcn@tN
a5ZU"6Hi
x4fl=
} /=I&-gxC
8Kt_irD
n.jF:
public String getSSiteURL() gQ4Q h;
{ R}njFQvS)
return sSiteURL; 2*Hw6@Jj
} _Qg^>}]A1
)k@W6N
BoZ])Y6=
public void setSSiteURL(String value) UOHU1.3$T
{ yE[ -@3v
sSiteURL = value; XlIRedZ{
} im{'PgiR
l0AgW_T
N p9N#m?
public String getSFilePath() 48dIh\TH"
{ #A<|&#hh
return sFilePath; +^tq?PfE
} 9XWHr/-_@
?Q1(L$-=
M,@\*qlEJ
public void setSFilePath(String value) 08AC9
{ y;Xb."e~
sFilePath = value; uU(G&:@
} a$ a+3}\
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public String getSFileName() q<`YJ,
{ V_f}Y8>e
return sFileName; Q!K@
} 9n{tbabJ
0STtwfTr:
{[WEA^C~Q
public void setSFileName(String value) ppr95Y]^
{ *O-1zIlp
sFileName = value; 2%4dA$H#4w
} f!hQ"1[
`:cnu;
`<&RZB2
public int getNSplitter() YW55iyM
{ '9^+J7iO(+
return nSplitter; m[ *)sm
} 0,+RF"R
?dMyhU}
-1).'aJ^
public void setNSplitter(int nCount) ,jJ&x7ra8
{ xc)A`(g
nSplitter = nCount; [1Pw2MC<
} j`jF{k b
} %!%G\nv
M{I8b<hY
-w nlJi1f
/* ~EJVlji
**Utility.java OB"Ur-hJ0
*/ 55xaZ#|
package NetFox; zf-)c1$*r
iu!j#VO
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public class Utility { \| qr&(PG
ERcj$ [:T(
~lO^C
public Utility() ,{wA%Oy,
{ h+EG) <
MX!t/&X(n
mlC_E)Ed5
} EfA*w/y
UHr0J jQK
//线程睡眠 ,iKEIxA!
public static void sleep(int nSecond) o&45y&
{ Q/[|/uNw?
try{ mqL&bmT
Thread.sleep(nSecond); UeNa
} cHN eiOF
catch(Exception e) <vS J<WY
{ b0W~*s [4
e.printStackTrace (); dH4wyd`
} pqmb&"l
} ')C%CAYW
#$q~ZKB
//日志 Q}ebw
public static void log(String sMsg) ",wv*z)_>
{ kmHIU}Z
System.err.println(sMsg); E/x2LYH
} e}|UVoeH
R5O{;/w
OcR6\t'
public static void log(int sMsg) sg@)IEg</v
{ kMD:~V
System.err.println(sMsg); z?o16o-:
} OVr, {[r
} K/oC+Z;K
"4W@p'
3`y9V2&b
/* fq^D<c{3
**TestMethod.java FPM@%U
*/ );4lM%]eb
package NetFox; ?.E ixGzI^
dWR0tS6vR`
w!$|IC
public class TestMethod { jKFypIZ4
QWt?` h=
B8Ob~?
public TestMethod() Vc}#Ok
{ ///xx/weblogic60b2_win.exe AvW2)+6G
try{ f{ZOH<"Lo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ` VL`8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L2"fO
SiteFileFetch fileFetch = new SiteFileFetch(bean); c.5?Q>!+
fileFetch.start(); 88fH!6b
} {XC1B
catch(Exception e){e.printStackTrace ();} *5( h,s3&
z+ybtS>pZ
dP8b\H
} *E"QFirk0
8KqrB!
oK;.|ja
public static void main(String[] args) 1r6>.&p
{ rLMjN#`^
new TestMethod(); 4k9O6
} :1Jg;G
} //C3tW
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