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)); L KR,CPz
} p}X87Zq
for(int i=0;i<nEndPos.length-1;i++) F4gc_>{|
{ {0{$.L
nEndPos = nStartPos[i+1]; bvTkSEN
} >9|+F[Fc
nEndPos[nEndPos.length-1] = nFileLength; 7Wn]l!
} $>m<+nai'
} a8c]B/
Nuq/_x
V#KM~3e
//启动子线程 DL{a8t1L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1_]l|`Po
for(int i=0;i<nStartPos.length;i++) ?&_\$L[
{ M/;g|J jM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Ux;dekz}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (Cd`~*5
nStartPos,nEndPos,i); -3Hq1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \C|06Bs$
fileSplitterFetch.start(); Vd~k4
} ~=*_I4,+r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =v9;HPiO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >?<d}9X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nfB9M1Svn
nEndPos = " + nFileLength); 5~QB.m,>
// fileSplitterFetch[nPos.length-1].start(); [%:NR
S0yT%V
\SR
//等待子线程结束 z>~3*a9&
//int count = 0; eyV904<F
//是否结束while循环 ysPW<
boolean breakWhile = false; ^\%%9jY
9 |Y?#oZ1
&5<lQ1
while(!bStop) {]]I4a
{ +/tD$
write_nPos(); V>Cf 8>m
Utility.sleep(500); xm5D$m3#
breakWhile = true; &-A7%"
EzaOg|
sMK/l @7
for(int i=0;i<nStartPos.length;i++) I(4k{=\ph]
{ \8!HZei
if(!fileSplitterFetch.bDownOver) hAdEq$
{ YX(%jcj*
breakWhile = false; [(mq8Nb
break; ?}.(k/
} g@L4G?hLn
} M}>q>
if(breakWhile) aum,bm/0J
break; =Ao;[j)*!
EMo6$(
\?ZdUY
//count++; V*N9D>C
//if(count>4) V4>P8cE
// siteStop(); G+}LLm.wX
} @N$r'@
tXx9N_/
|w5#a_adM
System.err.println("文件下载结束！"); 19EU[eb
} DCm;dh
catch(Exception e){e.printStackTrace ();} M\%{!Wzo8
} C"}x=cK
_F,OS<>
g 0L 4
//获得文件长度 [qz6_WOo
public long getFileSize() ">o/\sXeH
{ (R,eWWF8~
int nFileLength = -1; x[X.// :
try{ }fA3{Ro
URL url = new URL(siteInfoBean.getSSiteURL()); &Fi8@0Fh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /c7j@=0
httpConnection.setRequestProperty("User-Agent","NetFox"); ~?p > L
P/_XDP./U
X}ZOjX!
int responseCode=httpConnection.getResponseCode(); UaBR;v-.B3
if(responseCode>=400) ;9~z_orNQZ
{ `XnFc*L 1
processErrorCode(responseCode); U{x'@/Ld
return -2; //-2 represent access is error Xk3Ufz]QN
} v6GWD}HH,
LV[4zo]=
^ey\ c1K
String sHeader; Hq~ 2,#Ue
@.0,ka,X
sOJ~PRA
for(int i=1;;i++) ] !H<vR$8
{ rEViw?^KT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D"hiEz
//Utility.log(in.readLine()); 4@5<B
sHeader=httpConnection.getHeaderFieldKey(i); ql4T@r3l}3
if(sHeader!=null) 5u&jNU5m_
{ R[Rs2eS_
if(sHeader.equals("Content-Length")) r}991O<
{ kSDV#8uZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5mV'k"Om#"
break; czp5MU_^
} ZpdM[\Q-
} CI,-qi
else !>+ 0/
break; ka5>9E
} `SVR_
} R6!3Y/Q@
catch(IOException e){e.printStackTrace ();} Y,a.9AWw)
catch(Exception e){e.printStackTrace ();} ^,X+ n5q;m
H1w;Wb1se
eI[z%j[Y*
Utility.log(nFileLength); }A#FGH+
a}fW3+>
^8 z*f&g
return nFileLength; Cr&ua|%F
} 1?*vqdt
f ZISwr
*8Lym,]
//保存下载信息（文件指针位置） ]/a?:24[
private void write_nPos() @<YZa$`
{ ~(^[TuJC
try{ iD\joh-C
output = new DataOutputStream(new FileOutputStream(tmpFile)); GY!&H"%
output.writeInt(nStartPos.length); {S}/LSNB
for(int i=0;i<nStartPos.length;i++) -uh/W=Q1R
{ c>^_4QQ
// output.writeLong(nPos); WcdU fv(>
output.writeLong(fileSplitterFetch.nStartPos); T^79p$
output.writeLong(fileSplitterFetch.nEndPos); EH[?*>+s
} )~J/,\
output.close(); Q:-/@$&i
} Ah"RxA
catch(IOException e){e.printStackTrace ();} L4dbrPE*0
catch(Exception e){e.printStackTrace ();} M_PL{
} :s4CWEd
MXhS\vF#m
?GFVV->i
//读取保存的下载信息（文件指针位置） )~Q$ tM`
private void read_nPos() Ao,lEjNI
{ w0.#/6
try{ k'{lo_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3U}z?gP[
int nCount = input.readInt(); ?=\h/C
nStartPos = new long[nCount]; =\q3;5[
nEndPos = new long[nCount]; )Ev [o#y
for(int i=0;i<nStartPos.length;i++) UgUW4x'+
{ *"E]^wCn
nStartPos = input.readLong(); 0wc+<CUW
nEndPos = input.readLong(); Q8P;AN_JS
} $k!t&G
input.close(); Y!SD^Ie7!
} oc15!M3$
catch(IOException e){e.printStackTrace ();} I*0W\Qz@
catch(Exception e){e.printStackTrace ();} f[X>?{q
} <=0_[M
L5>>gG,
M#:Mwa$
private void processErrorCode(int nErrorCode) ;z&p(e
{ 9zX\ioT
System.err.println("Error Code : " + nErrorCode); #-@dc
} - @
jdhhvoQ
OnD+/I
//停止文件下载 Z3I<
public void siteStop() t4,6`d?C
{ H >RGX#|
bStop = true; ysSEgC3
for(int i=0;i<nStartPos.length;i++) f}@]dFr
fileSplitterFetch.splitterStop(); [jafPi(#g
8(ZQD+U(9F
T,;6q!s=
} rR."_Z2
} yy%J{;
//负责部分文件的抓取 p[W8XX
**FileSplitterFetch.java fIFB"toiPE
*/ ZZ4W?);;
package NetFox; X3'z'5
]0\8g=KK
Iy"
import java.io.*; $rf5\_G,96
import java.net.*; n#m )]YQC
u dH7Q&"
d]+g3oy `
public class FileSplitterFetch extends Thread { YKj7~yK?
6n<:ph,h;
Ll&Y_Ry
String sURL; //File URL ;@Ls"+g
long nStartPos; //File Snippet Start Position IspY%UMl
long nEndPos; //File Snippet End Position (2<0kqj%
int nThreadID; //Thread's ID /SZsXaC '
boolean bDownOver = false; //Downing is over 4,FuQ}
boolean bStop = false; //Stop identical I2D<~xP~2+
FileAccessI fileAccessI = null; //File Access interface fNQ.FAK":
E@t^IGDr
e PlEd'Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @|r*yi
{ ~,dj)x 3M
this.sURL = sURL; RaG-9gujI
this.nStartPos = nStart; nz+DPk["
this.nEndPos = nEnd; .LdLm991,Y
nThreadID = id; ;clF\K>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =XyK/$
} Gv3a<Knn4
G{YLyl/9
7@MVInV9
public void run() irpO(>LK
{ |Q.t]TR'P
while(nStartPos < nEndPos && !bStop) 6i,d|
{ hyFq>XFo
EcFYP"{U
y~''r%]
try{ <#LHL
URL url = new URL(sURL); _qM'm^z5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3,W2CN}
httpConnection.setRequestProperty("User-Agent","NetFox"); |$^,e%bE
String sProperty = "bytes="+nStartPos+"-"; {WT"\Xj>B?
httpConnection.setRequestProperty("RANGE",sProperty); 7[^:[OEE
Utility.log(sProperty); 8Q?)L4.]
E~jNUTq
cBiv=!n
InputStream input = httpConnection.getInputStream(); &EV|knW
//logResponseHead(httpConnection); 9kWyO:a_(
"pQM$3n(
s>E4.0[I%
byte[] b = new byte[1024]; JaiYVx(
int nRead; o~2bk<]z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *!Vic#D%
{ tbl!{Qwx
nStartPos += fileAccessI.write(b,0,nRead); i=]IUjx<
//if(nThreadID == 1) C.FGi`rrm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dGrOw)
} qXCl6Yo8
{.DI[@.g
45W:b/n\
Utility.log("Thread " + nThreadID + " is over!"); ?20y6c<
bDownOver = true; r"zW=9 O=
//nPos = fileAccessI.write (b,0,nRead); WQ|d;[E
} &7XB$
catch(Exception e){e.printStackTrace ();} cg}46)^<QH
} !nU
} 2P"@=bYT"
7a->"W
*(& J^
//打印回应的头信息 p$0;~1vH
public void logResponseHead(HttpURLConnection con) :DR G=-M
{ 8~Rja
for(int i=1;;i++) vFV->/u
{ N|WnUlf]:
String header=con.getHeaderFieldKey(i); [="moh2*f
if(header!=null) Yono8M;9*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {uDL"~^\
Utility.log(header+" : "+con.getHeaderField(header)); oy;N3
else plv"/KJM
break; 8n,i5>!d
} s[SzE6eQ`l
} pIqPIuy
axxdW)+K
3Yp_k
public void splitterStop() jgs kK
{ ghx8dX}
bStop = true; +[zrU`!@
} LyS139P$
0v,DQJ?w8
Mw\/gm_3
} L`V6\Ix(I
v}M, M&?
vpMNulXb,
/* a+{YTR>0m
**FileAccess.java >6@*%LM
*//文件访问(定位，写) 3BKW
package NetFox; qF%wl
import java.io.*; 3Nsb@0
/ZvNgaH5M
Rl=NVo
public class FileAccessI implements Serializable{ H]mY6D51"
o{f n}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7: J6 F
RandomAccessFile oSavedFile; jQ4Pv`
long nPos; X. UN=lu
1;?b-FEq:
U:J~Oy_Z
public FileAccessI() throws IOException O8[dPmW
{ j0kEi+!TVq
this("",0); '355Pce/
} 7>9/bB+TL
c42p>}P[
8T&m{s
public FileAccessI(String sName,long nPos) throws IOException &rq7;X
{ H-1@z$p
oSavedFile = new RandomAccessFile(sName,"rw"); ?Xlmt$Jp
this.nPos = nPos; P+%O]v1 Ob
oSavedFile.seek(nPos); 1k-^LdDj
} o5BOe1_Pw
2a (w7/W:
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public synchronized int write(byte[] b,int nStart,int nLen) Jn'q'+
{ zblh_6
int n = -1; K%2,z3ps
try{ QEQ8gfN9>
oSavedFile.write(b,nStart,nLen); P2 !~}{-
n = nLen; M\enjB7k
} 8p-5.GU)<e
catch(IOException e) _@F4s
{ wAF>C[<\
e.printStackTrace (); v$+G_@
} a_x$I?,
sN5x\9U
sOzjViv
return n; p%xo@v(
} T~ /Bf
I@pnZ-5
C/<fR:`c
} lY?TF
e}(.u1
jcXb@FE6
/* gS4K](KH |
**SiteInfoBean.java UF D_
*/ $daI++v`
package NetFox; N]KqSpPh
X H{5E4P
43,- t_jV
public class SiteInfoBean { 8%arA"#S
,(OA5%A9zK
6;*tw i
private String sSiteURL; //Site's URL ;9,Ll%Lk<
private String sFilePath; //Saved File's Path \<i#Jn+)
private String sFileName; //Saved File's Name (0Hhn2JA
private int nSplitter; //Count of Splited Downloading File ;6fkG/T
q'C'S#qqn
4>0xS-
public SiteInfoBean() n." j0kc7=
{//nSplitter的缺省值为5 1V FAfv%}
//default value of nSplitter is 5 Y($"i<rN
this("","","",5); + #S]uC
} !%T@DT=l&
'ZL)-kbI
/3FC@?l w4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9 r+' o#
{ z#D@mn5\a
sSiteURL= sURL; x*Z"~'DI
sFilePath = sPath; CDU^X$Q
sFileName = sName; 3zs~Y3M?i
this.nSplitter = nSpiltter; A3C<9wXx
mfeyR
Tg{d#U_qB
} bL swq
2s|[!:L5
FIC 2)
public String getSSiteURL() &EA4`p
{ 4A|5eg9N
return sSiteURL; Kc{fT^E
} `A&64D
h=d&@k\g
v,Ep2$
public void setSSiteURL(String value) ]E[Mv} =
{ !Aj_r^[X`
sSiteURL = value; `S$BBF;
} /SlCcozFL~
al#yc
Rjm5{aa-
public String getSFilePath() z~z.J]
{ cN&b$8O=%
return sFilePath; PS(LD4mD
} O23f\pm&
2)4{
&qrH
public void setSFilePath(String value) `(*5yXC
{ &W".fRH_O
sFilePath = value; 7/Ve=7]
} EG<K[t
Hr96sN.R
/+02BP
public String getSFileName() 7th&C,c&
{ x<9|t(
return sFileName; {,P&05iSi
} L7a+ #mGE
+de.!oY
!C#q
public void setSFileName(String value) 0r:8ni%cL
{ X} 8rrC=
sFileName = value; N @]*E
} 4vE,nx=
?$=N!>P#
i aP+Vab
public int getNSplitter() P%%Cd
{ d-xKm2sH
return nSplitter; 8c]\4iau
} N \A)P
!7^fji
Q$Vxm+
public void setNSplitter(int nCount) "6Ly?'HK
{ 1c?,= ;>
nSplitter = nCount; 8l;0)`PU
} NTgk0cq
} o` ,&yq.
k{"~G#GwP
YR~g&E#U^
/* 3vVhE,1N
**Utility.java s+Ln>c'|o
*/ Xo{Ce%L
package NetFox; z\fD}`^8
nSgg'I(
tty6
public class Utility { < ~x5{p
Njz,y}\
q& 4Z.(
public Utility() _qJ[~'m<^C
{ :vX;>SH$p
H\^5>ccU>V
q0DoR@
} ruF+X)
P%B1dRa
//线程睡眠 Gash3}+
public static void sleep(int nSecond) 83;1L:}`
{ D.R5-
try{ _.Uz!2
Thread.sleep(nSecond); Kq6m5A]z
} r/3!~??x
catch(Exception e) i!YZF$|
{ vAwFPqu
e.printStackTrace (); OdwSNG
} J6NQ5S\
} D95$
A 7DdUNR
//日志 ^D oJ='&
public static void log(String sMsg) S,Zjol%p
{ fbo64$!hZ
System.err.println(sMsg); .F)--%
} ^b>E_u
90I)"vfW5
_[XEL+.
public static void log(int sMsg) ~LYKt0/W&
{ (IJf2
System.err.println(sMsg); hO{@!H$l
} De:w(Rm
} },[S9I`p
Zb);08X
JR7~|ov
/* K%Q^2"Eb0
**TestMethod.java #J^p,6
*/ { H9pF2C
package NetFox; \2eYw.I=
?ADk`ts~,}
9n8;eE08
public class TestMethod { 3%|<U51
}1;Ie0l=_e
'*-X3p
public TestMethod() HT1bsY 0t
{ ///xx/weblogic60b2_win.exe mpr["C"l
try{ jGt'S{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o~es>;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &[RC4^;\V
SiteFileFetch fileFetch = new SiteFileFetch(bean); :p8JO:g9
fileFetch.start(); )#*c|.
} A=h`Z^8\B
catch(Exception e){e.printStackTrace ();} 9h*$P:S;1v
)](8{}wo
>(%im:_
} }zLe;1Tx
0Vy* 0\{S
/hI#6k8o_
public static void main(String[] args) %R&3v%$y*
{ X4%*&L
new TestMethod(); .iew5.eB+
} \dufKeiS&a
} g`J? 2 _]
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