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)); UDG1F_&h
} 9)oi_U.
for(int i=0;i<nEndPos.length-1;i++) r%=-maPL[
{ ^`kwSC
nEndPos = nStartPos[i+1]; b-<0\@`Z#
} =5\*Zh1
nEndPos[nEndPos.length-1] = nFileLength; %'iJVFF
} V5K/)\#
} 0>od1/`
kGV:=h
MrR`jXz
//启动子线程 i3w~&y-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^{uHph9ny
for(int i=0;i<nStartPos.length;i++) QJ XP-
{ <<0sv9qw1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \\k=N(n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <Z%=lwtX
nStartPos,nEndPos,i); ,\6Vb*G|E>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 712nD ?>
fileSplitterFetch.start(); P2'N4?2
} (mIjG)4t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R/oi6EKv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j0e,>X8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kkjugm{D7
nEndPos = " + nFileLength); E2dM0r<]
// fileSplitterFetch[nPos.length-1].start(); Z^|N]Ej
s\;/U|P_
Tgz=I4g
//等待子线程结束 $2a"Ec!7
//int count = 0; e\V -L_
//是否结束while循环 2Xe1qzvo
boolean breakWhile = false; v[Q)L!J1
i#la'ICwJ
O>h`
while(!bStop) I0+6p8,
{ ]Ucw&B*@
write_nPos(); CGi;M=xr
Utility.sleep(500); v@=qVwX
breakWhile = true; @-sWXz*W
S9Sgd&a9
P PJ^;s
for(int i=0;i<nStartPos.length;i++) Yj@Sy
{ Xfk DMh
if(!fileSplitterFetch.bDownOver) T`E0_ZU;
{ ,m{R m0
breakWhile = false; ,ucRQ&P
break; ^sf,mM~D
} (xb2H~WrN
} _f^6F<!
if(breakWhile) +cH>'OXoB
break; iAz0 A
fmixWL7.Zg
?0; 2ct
//count++; TaRPMKk
//if(count>4) Z[nHo'
// siteStop(); p}QDX*/sSu
} w1tM !4r
zP44 Xhz
3Z?ornS
System.err.println("文件下载结束！"); 5mZ2CDV
} ;].X;Ky<
catch(Exception e){e.printStackTrace ();} NA0nF8ek
} $9X+dvu*
6.)ug7aF
1D'r;`z
//获得文件长度 2K9X(th1
public long getFileSize() !'N@ZZ
{ m54>}
int nFileLength = -1; #4Z e2T|
try{ 1b~21n
URL url = new URL(siteInfoBean.getSSiteURL()); #+ch
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @S@VsgQ%3Z
httpConnection.setRequestProperty("User-Agent","NetFox"); !.'D"Me>
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1'o[9-
int responseCode=httpConnection.getResponseCode(); C][$0
if(responseCode>=400) ?>B?*IK!
{ -~]H5er`
processErrorCode(responseCode); Mc,|C)
return -2; //-2 represent access is error F-s{#V1=
} y$%oR6K7-
7Y8~")f
%C/p+Tg
String sHeader; #%[;vK
on7 n4
v":q_w<k
for(int i=1;;i++) K%dQ;C*?
{ ],weqs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a<&K^M&
//Utility.log(in.readLine()); Oo :Dt~Ib
sHeader=httpConnection.getHeaderFieldKey(i); d3c.lD)L9
if(sHeader!=null) A&M_ J
{ _3aE]\O[
if(sHeader.equals("Content-Length")) A1prYD
{ s6~;)(r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W/,bz",v3
break; vQ}ZfP
} x#`p.sfVo
} Z9DfwWI2nu
else N)"8CvQL
break; :Dty([
} n0lOq
} 84WDR?
catch(IOException e){e.printStackTrace ();} Oz6$u
catch(Exception e){e.printStackTrace ();} 9I/l+IS"X
+g g_C'"
!CU-5bpu
Utility.log(nFileLength); DU\ytD`u
KyNu8s k
K[icVT2v~
return nFileLength; Q/SO%E`E
} )Dz]Pv]H'
VZt%cq
Wo "s;Z
//保存下载信息（文件指针位置） e8<}{N0,n
private void write_nPos() HF*0
{ C7dq=(p&
try{ Q#3}AO
output = new DataOutputStream(new FileOutputStream(tmpFile)); @4y?XL(n
output.writeInt(nStartPos.length); Aars\
for(int i=0;i<nStartPos.length;i++) ',R%Q0Q
{ s;I @En
// output.writeLong(nPos); C$[iduS
output.writeLong(fileSplitterFetch.nStartPos); `o{ Z;-OF
output.writeLong(fileSplitterFetch.nEndPos); 7"'RE95
} >UCg3uFj
output.close(); TnN ythwZ
} nook/7]
catch(IOException e){e.printStackTrace ();} :k_&Zd j,B
catch(Exception e){e.printStackTrace ();} i(|ug_^
} a(vt"MQ_
IVPN=jg?
#r#[&b
//读取保存的下载信息（文件指针位置） ]jD\4\M}
private void read_nPos() 1Rd|P<y
{ -rU_bnm
try{ \OVFZ D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;D~#|CB
int nCount = input.readInt(); NWn*_@7;
nStartPos = new long[nCount]; QQW}.>N
nEndPos = new long[nCount]; :6(\:
for(int i=0;i<nStartPos.length;i++) )G)6D"5,+G
{ dE"_gwtX
nStartPos = input.readLong(); uaO.7QSwN
nEndPos = input.readLong(); "Vq= Ph
} J>v[5FX+
input.close(); Md~SzrU
} aM $2lR])J
catch(IOException e){e.printStackTrace ();} ')v,<{
catch(Exception e){e.printStackTrace ();} O4X03fUx
} gbzBweWF
c?CD;Pk
rx9*/Q0F
private void processErrorCode(int nErrorCode) p(pfJ^/:(
{ 8vuTF*{yZ
System.err.println("Error Code : " + nErrorCode); o6A$)m5V
} HVus\s\&y%
MU$tX
u~OlJ1V
//停止文件下载 T!,5dt8L
public void siteStop() ,;t:x|{%
{ ntH`\ )xi
bStop = true; B}TY+@
for(int i=0;i<nStartPos.length;i++) i6HRG\9nU
fileSplitterFetch.splitterStop(); ~qqxHymc
<<LLEdB
bRu9*4t
} Z5v_- +K
} r\"R?P$y|
//负责部分文件的抓取 FXo.f<U
**FileSplitterFetch.java KNmU2-%l
*/ z6U'"T"a
package NetFox; DyqqY$ vH(
In1{&sS
RVAku
import java.io.*; SY5}Bu#
import java.net.*; (xW+* %
=u}~\ 'd
nT> v
public class FileSplitterFetch extends Thread { ke2dQ^kc4
9xbT?$^
:jv(-RTI
String sURL; //File URL L'Cd`.yVO
long nStartPos; //File Snippet Start Position 6qDt6uB
long nEndPos; //File Snippet End Position %!t9)pNc
int nThreadID; //Thread's ID #~'d Y\&
boolean bDownOver = false; //Downing is over #qVTB@d
boolean bStop = false; //Stop identical 9@CRL=
FileAccessI fileAccessI = null; //File Access interface h rSH)LbJ
J\@g3oGw
B{=DnB6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SWw!s&lP&
{ J.JD8o9sa
this.sURL = sURL; bz>\n"'
this.nStartPos = nStart; K W&muD
this.nEndPos = nEnd; C5^WJx[
nThreadID = id; q>(?Z#sB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ((`\i=-o5
} )&T 5/+
?u#s?$Y?
K9ia|2f
public void run() |9XoRGgXU
{ v_Vw!u
while(nStartPos < nEndPos && !bStop) YD[AgToo0
{ ]*=!lfrV
=iB[sLEJ
kk`K;`[tB
try{ lwfS$7^P
URL url = new URL(sURL); 4*Hzys[{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +JYb)rn$^
httpConnection.setRequestProperty("User-Agent","NetFox"); tRI<K
String sProperty = "bytes="+nStartPos+"-"; "y~*1kBu
httpConnection.setRequestProperty("RANGE",sProperty); ^Lb\k|U,\
Utility.log(sProperty); 2'=)ese
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cEa8l~GC<
InputStream input = httpConnection.getInputStream(); Fy\q>(v.
//logResponseHead(httpConnection); Jvc<j:{^w
vWmp?m
tW~kn9glZ
byte[] b = new byte[1024]; pNd`fV#jX
int nRead; #C }+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \xp0n
{ "0%K3d+
nStartPos += fileAccessI.write(b,0,nRead); )U|V|yem'
//if(nThreadID == 1) W5'6L=WG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .WKJ37od
} 9nVb$pfe#
;@k=9o]A
1c QF(j_
Utility.log("Thread " + nThreadID + " is over!"); .aO6Y+Y
bDownOver = true; y@v)kN)Y9\
//nPos = fileAccessI.write (b,0,nRead); {HY3E}YJL
} <ot`0
catch(Exception e){e.printStackTrace ();} 'y!qrmMRr
} 5|0/$ SWd*
} 6p }a!
+x{o
>}f!. i
//打印回应的头信息 gdD|'h
public void logResponseHead(HttpURLConnection con) W8QP6^lY
{ R\ 8[6H
for(int i=1;;i++) EGI$=Y
{ _R(ZvsOZ
String header=con.getHeaderFieldKey(i); .lj5pmD
if(header!=null) Y[)mHs2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nHeJ20
Utility.log(header+" : "+con.getHeaderField(header)); xO:h[
else ?8kFAf~
break; XK\nOHLS
} l'4<^q
} >Z*b0j
ZDaHR-%Y
d)U(XiK'
public void splitterStop() | eCVq(R
{ UTE6U6
bStop = true; j~Fd8]@
} [Y!HQ9^LEp
XM5)|D
':}9>B3 S
} h/A\QW8Sd
;]xc}4@=mg
C3^3<
/* } *)l
**FileAccess.java &Y@),S9
*//文件访问(定位，写) SVwxK/Fci
package NetFox; ]r!|@AWrQ\
import java.io.*; bBML +0a
!BW!!/U
b=BNbmX
public class FileAccessI implements Serializable{ 8J&9}@y
h #gI1(uL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +C;;4s)
RandomAccessFile oSavedFile; [4C_iaE
long nPos; d, g~.iS~
%pWJ2J@
}R}M>^(R4
public FileAccessI() throws IOException 6oQ7u90z*
{ y`$qcEw
this("",0); n~ $S
} aC=2v7*
!Z>,dN
#tUhul/O
public FileAccessI(String sName,long nPos) throws IOException TDfloDxA
{ `qd5+~c
oSavedFile = new RandomAccessFile(sName,"rw"); 9$U>St
this.nPos = nPos; .<%q9Jy#
oSavedFile.seek(nPos); 7hx^U90K
} F$4=7Njv
h&i(Kfv*
FZU1WBNL%t
public synchronized int write(byte[] b,int nStart,int nLen) X&aQR[X
{ FTEC=j$ln
int n = -1; /g*_dH)=
try{ 6(?@B^S>2
oSavedFile.write(b,nStart,nLen); ^F?B_'
n = nLen; x&u@!# d]
} 7>@0nHec
catch(IOException e) 20$Tky_
{ ik?IC$*n3i
e.printStackTrace (); .e5@9G.jb
} B!`.,3
BQUYT/$(
a'-xCV|^
return n; jxW/"Q
} )IK%Dg(v
E)Qg^DHP/
h8p{
} Xo(W\Pes
JcP<@bb>B
HL[V}m
/* S.iUiS"
**SiteInfoBean.java k}kwr[
*/ G,Yctv
package NetFox; Z>w@3$\z
:-+][ [
hC{2LLu;n
public class SiteInfoBean { q4@+Pi)
Bk.`G)t
-$%~EY}
private String sSiteURL; //Site's URL 9\Rk(dd
private String sFilePath; //Saved File's Path wrCV&2CG
private String sFileName; //Saved File's Name <MO40MP
private int nSplitter; //Count of Splited Downloading File ;>>:7rdYt
z,C>Rh9Id
b;;y|H
public SiteInfoBean() 6,CK1j+tZ
{//nSplitter的缺省值为5 Yx. t+a-
//default value of nSplitter is 5 #0*I|gfV
this("","","",5); n|=yw6aV'
} b!SIs*
V^.Z&7+E`_
2&s(:=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T|oDJ]\J
{ /YwwG;1
sSiteURL= sURL; Z^mIGy}
sFilePath = sPath; %^I 7=
sFileName = sName; ,-$%>Uv
this.nSplitter = nSpiltter; P:'y}a-
}EfRYE$E
b[n6L5P5m2
} @ohJ'
'@hnqcqXq
A-\n"}4
public String getSSiteURL() JZyEyN
{ [sPLu)q2
return sSiteURL; 75Bn p9
} =5pwNi_S
)d {8Cu6
Y'6P ~C;v
public void setSSiteURL(String value) u4=ulgi
{ hoPh#? G
sSiteURL = value; .b*-GWx
} JKXIxw>q
_#P5j#
eBECY(QMQ
public String getSFilePath() g2r8J0v
{ =o"sBVj
return sFilePath; %HZ!s `w_
} \=W t{
{2|sk9?W
lQ.3_{"s
public void setSFilePath(String value) /KJWo0zo
{ Tc;BE
sFilePath = value; 9fSX=PVRmQ
} uTrGb:^
rPW9lG
%%O_:@9x,
public String getSFileName() c$hoqi |tD
{ y3V47J2o
return sFileName; c%n%,R>
} #0qMYe>Y
exm*p/
C\[g>_J
public void setSFileName(String value) Q},uM_"+
{ fV/
sFileName = value; LTD;
} <8Q?kj
!%C&hH\
*UG=dl#F#
public int getNSplitter() ZcN%F)htm
{ O >&,h^
return nSplitter; WgV[,(
} +7)/SQM5
w\.z-6G
<J1$s_^`
public void setNSplitter(int nCount) !3at(+4
{ dNs<`2m
nSplitter = nCount; KI<Vvcm
} BtWm ZaKi
} j\@|oW0
~hA;ji|I
oakm{I|k}
/* L@5g#mSl
**Utility.java Zo(QU5m0
*/ Uefw
package NetFox; obIYC
!}uev
;,_c1x/F
public class Utility { J 9k~cz
! XNTk]!
9o5_QnGE
public Utility() le`_
{ gI~jf- w
G9\@&=
lhV'Q]s@6
} .7GAGMNS
R_DZJV O
//线程睡眠 oG;;='*
public static void sleep(int nSecond) V$ss[fX
{ b<rJ@1qtJ
try{ _52BIrAO2
Thread.sleep(nSecond); thSo,uGlW
} )wYbcH
catch(Exception e) 80ms7 B
{ M}6? |ir
e.printStackTrace (); B\!.o=<h
} u>-!5=D8
} 'xp&)gL
r*l:F{
//日志 Aa/lKiiz
public static void log(String sMsg) lN^} qg><
{ !=c&U.B
System.err.println(sMsg); #(NkbJ5ka
} BK:S:
_-I0f##.
3F0:v,+;
public static void log(int sMsg) \TBY)_[ {
{ "&/&v
System.err.println(sMsg); I806I@ix
} $.@)4Nu!_
} @v,qfT*k7
MoP0qNk
M9b_Q
/* V<!E9/4rS
**TestMethod.java fOyLBixR
*/ l;g8_uyjv7
package NetFox; .<`Rq'
L~jKx)S%
IZ6[|Ach6
public class TestMethod { V+l>wMeo
Et+N4w
.ZrQ{~t
public TestMethod() ^dR5fAS
{ ///xx/weblogic60b2_win.exe z_J"Qk
try{ d98ZC+q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }A"%YDrNbG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )xQA+$H#4
SiteFileFetch fileFetch = new SiteFileFetch(bean); }0Q6iHX@
fileFetch.start(); 1vQj` F
} [Hww3+~+
catch(Exception e){e.printStackTrace ();} ukSi9| 1-,
8W"~>7/>D
eS jXaZh
} *lIK?"mo
`_'I 9,.a
d(L u|/~
public static void main(String[] args) { LJRdV
{ YDyi6x,
new TestMethod(); BjR:#*<qD
} bgm$<;`U
} ?8X+)nU@
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