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)); (yCFpb
} #|34(ML
for(int i=0;i<nEndPos.length-1;i++) ;z>)&F
{ hX]vZR&R
nEndPos = nStartPos[i+1]; (<pc4#B@*
} =$IjN v(?
nEndPos[nEndPos.length-1] = nFileLength; 40oRO0p
} -Vk+zEht
} nqt;Ge M
&V[m{.
2*5Z| 3aX
//启动子线程 ~w'M8(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t+5JIQY>
for(int i=0;i<nStartPos.length;i++) RJ1Q.o
{ -1~bWRYq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mjrl KI}f/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $z]gy]F
nStartPos,nEndPos,i); Cw`v\ 9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E3y"
fileSplitterFetch.start(); g&H6~ +\
} `6b!W0$ -
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }r6SV%]:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HP2]b?C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #m6 eG&a
nEndPos = " + nFileLength); #n7uw
// fileSplitterFetch[nPos.length-1].start(); "EQ-`b=I4
X6/k `J
E/9 U0
//等待子线程结束 _pM&Ya
//int count = 0; C$xU!9K[+
//是否结束while循环 M& GA:`
boolean breakWhile = false; cTFyF)
=m=`|Bn
!12W(4S5
while(!bStop) H~1*`m
{ -#H>kbs
write_nPos(); ^S'}RZ*>
Utility.sleep(500); Ft>Abj,6
breakWhile = true; $6T*\(;T@A
`itaQGLD
oW(p (>
for(int i=0;i<nStartPos.length;i++) yw2^kk93|
{ c-!rJHL`
if(!fileSplitterFetch.bDownOver) T%Vii*?M
{ #vYdP#nWb
breakWhile = false; Nrva?W_i
break; Iw8;",e2
} tB4- of3+
} a5:Q%F<!
if(breakWhile) %lAJ]$m
break; Zg%U4m:
l~wx8 ,?G
P}y}IR{6
//count++; ^_r8R__S:
//if(count>4) eXWiTi@
// siteStop(); _) 2fXG!
} l=[<gPE
=9GL;z:R+
0Np}O=>
System.err.println("文件下载结束！"); 9`+c<j4/B
} a1B_w#?8
catch(Exception e){e.printStackTrace ();} &96I4su
} -kxNJ Gc?
qdrk.~_
1Dg\\aUk
//获得文件长度 6+A<_r`#Q
public long getFileSize() 8*I43Jtlf,
{ ?h"+q8&
int nFileLength = -1; Xz&Hfs"/J
try{ &!vJ3:
URL url = new URL(siteInfoBean.getSSiteURL()); kN>%y&cK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c%r?tKG6
httpConnection.setRequestProperty("User-Agent","NetFox"); &xMR{:
pj G6v(zK
8E"Ik~
int responseCode=httpConnection.getResponseCode(); UMuqdLaT9
if(responseCode>=400) Gvw4ot/
{ ~mx me6"v
processErrorCode(responseCode); 7OG=LF*V-
return -2; //-2 represent access is error aR ao\Wp|
} p#)u2^
V|ax(tHv
2cr~/,YY
String sHeader; ^[Cpu_]D
R_:47.qq
UP}Ys*
for(int i=1;;i++) <Vm+Lt9
{ 2?58=i%b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tzJdUZJ
//Utility.log(in.readLine()); \,i9m9;y
sHeader=httpConnection.getHeaderFieldKey(i); aG}ju;
if(sHeader!=null) : I28Zi*
{ ao#{N=mn
if(sHeader.equals("Content-Length")) >xws
{ gEbe6!; q3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a H'iW)
break; QpwOrxI}
} t/LQ|/xo
} fGHYs
else _?kjIF
break; &WE|9
} vF0#]
} 4=td}%
catch(IOException e){e.printStackTrace ();} I4:4)V?
catch(Exception e){e.printStackTrace ();} hC?:XVt
^&buX_nlO
u~7mH
Utility.log(nFileLength); G < Z)y#
xQ9P'ru
M?Tb9c?`
return nFileLength; T_|%nF-+
} '8K5=|!J
"i_I<?aGB
~+}w>jIm{|
//保存下载信息（文件指针位置） l5QH8eNwME
private void write_nPos() e3,TY.,Ay
{ x1</%y5ev
try{ ?pn<lW8d
output = new DataOutputStream(new FileOutputStream(tmpFile)); L|.q19b*
output.writeInt(nStartPos.length); W~(@*H
for(int i=0;i<nStartPos.length;i++) @^]wT_r
{ _^;+_6&[
// output.writeLong(nPos); l{ja2brX
output.writeLong(fileSplitterFetch.nStartPos); Osncl5PD)
output.writeLong(fileSplitterFetch.nEndPos); u:AKp<'
} H6%QM}t
output.close(); G66sPw
} huFT_z_;;
catch(IOException e){e.printStackTrace ();} @q:v?AO
catch(Exception e){e.printStackTrace ();} L[o;@+32
} {\z&`yD@
u UXj
gsFyZ
//读取保存的下载信息（文件指针位置） 5Z"IM8?
private void read_nPos() ,PC'xrEo
{ gv)F`uRWA
try{ 3SI:su
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FN jT?*
int nCount = input.readInt(); ^*JpdmVhu
nStartPos = new long[nCount]; nF$n[:
nEndPos = new long[nCount]; !lxs1!:
for(int i=0;i<nStartPos.length;i++) )c|S)iJ7=z
{ 7{F(NJUO1
nStartPos = input.readLong(); *FhD%><
nEndPos = input.readLong(); Axp#8
} Z3jh-{0
input.close(); lO=+V 6
} !Rp
catch(IOException e){e.printStackTrace ();} }?[^q
catch(Exception e){e.printStackTrace ();} s}"5uDfn1F
} )Dn~e#
bz5",8Mn
E.~;
private void processErrorCode(int nErrorCode) ~q0g7?}&
{ ">pW:apl%
System.err.println("Error Code : " + nErrorCode); 4cZig\mE;
} &G63ReW7 @
vn oI.;H,
yLv jfP1
//停止文件下载 _D{zB1d\0
public void siteStop() ;/tZsE{
{ Bfh[C]yy
bStop = true; iV+'p->/
for(int i=0;i<nStartPos.length;i++) J6m`XC
fileSplitterFetch.splitterStop(); jC_7cAsl
VjZ_L_U}
z3F ^OU
} #bRr|`
} x0t&hY>P!
//负责部分文件的抓取 W40GW
**FileSplitterFetch.java +a'QHtg
*/ ;=rMIi
package NetFox; ,$;g'z!N
*7`N^e
aFkxR\x 6%
import java.io.*; XD1x*#
import java.net.*; _-NS-E
sU7>q}!
$`nKq4Y
public class FileSplitterFetch extends Thread { 79.J`}#
{HgW9N(
iU)-YFO
String sURL; //File URL = mnjIp
long nStartPos; //File Snippet Start Position 3F%Qq7v
long nEndPos; //File Snippet End Position $}[Tj0+:
int nThreadID; //Thread's ID $Cu/!GA4.>
boolean bDownOver = false; //Downing is over ^RN1?dXA
boolean bStop = false; //Stop identical jgiP2k[Xom
FileAccessI fileAccessI = null; //File Access interface 4SG22$7W
)9,*s!)9
E)(`Z0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Dl862$_Q
{ #=WDJT:
this.sURL = sURL; Q]*YIb~D
this.nStartPos = nStart; NJYx.TL
this.nEndPos = nEnd; lYd#pNN
nThreadID = id; ^q"wd?((h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?e|'I"
} M mg#Vy~
o3H+.u$
Z2chv,SqCJ
public void run() l<<G".?
{ 0/.#V*KM
while(nStartPos < nEndPos && !bStop) B0c}5V
{ lY}mrb
,2>:h"^
mRCgKW<
try{ p71%-nV
URL url = new URL(sURL); RJs_ S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XEqg%f
httpConnection.setRequestProperty("User-Agent","NetFox"); X.0/F6U
String sProperty = "bytes="+nStartPos+"-"; 1A23G$D
httpConnection.setRequestProperty("RANGE",sProperty); H+zn:j@~L
Utility.log(sProperty); $"{V],:T |
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+DKrX
InputStream input = httpConnection.getInputStream(); &QOob)
//logResponseHead(httpConnection); 0:G@a&Lr
T4 SByX9
tYfhKJzGC
byte[] b = new byte[1024]; /3%]Ggwe
int nRead; -b@E@uAX/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +ZXGT
{ y_"GMw
nStartPos += fileAccessI.write(b,0,nRead); >ge-yK 1
//if(nThreadID == 1) 8O{]ML
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qn@Qd9Sf
} *DkA$Eu3u
kt1f2cj
nVG\*#*]|
Utility.log("Thread " + nThreadID + " is over!"); @n(=#Q3
bDownOver = true; ]_BG"IR!..
//nPos = fileAccessI.write (b,0,nRead); f.jAJ; N>
} af{;4Cr
catch(Exception e){e.printStackTrace ();} va8:QHdU
} [ur/`
} CjQ_oNI
QBto$!})
q1dYiG.-Z
//打印回应的头信息 n2#uH
public void logResponseHead(HttpURLConnection con) @=wAk5[IN
{ !^axO
for(int i=1;;i++) 8Z3+S)6
{ D~f.)kkC4
String header=con.getHeaderFieldKey(i); 8gC(N3/E"
if(header!=null) C,PCU<q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dc&Qi_W
Utility.log(header+" : "+con.getHeaderField(header)); x6DH0*[.
else 1rPeh{SZ
break; mA^>Y_:
} 6\o.wq
} YSrFHVq
z5'VsK:
l"*>>/U k
public void splitterStop() uaDU+ywL
{ R:.7c(s
bStop = true; /v!H{Zw=c
} L0&!Qct
C)C;U&Qd
}Xc|Z.6
} E"G._<3J8
D 0n2r
D[-Ct
/* D[tGbk
**FileAccess.java }p- %~Y
*//文件访问(定位，写) B!tte)
package NetFox; A`N;vq,
import java.io.*; [\.>BK
H>7!+&M
fGe{7p6XV*
public class FileAccessI implements Serializable{ (u'/tNGS
0~S<}N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pH~JPNng
RandomAccessFile oSavedFile; ',&MYm\
long nPos; ;q^YDZ'
=:0(&NCRq
VmT5?i
public FileAccessI() throws IOException ih;TQ!c+b
{ uBMNkN8
this("",0); O~Fk0}-
} QV 'y6m\
ut,"[+J
kt:%]ZZL
public FileAccessI(String sName,long nPos) throws IOException T a[74;VO
{ T6,lk1S'=
oSavedFile = new RandomAccessFile(sName,"rw"); (Z5#;rgem
this.nPos = nPos; Uh8ieb
oSavedFile.seek(nPos); "nefRz%j+
} e^an` </{
[}Iq-sz;0
F>Oh)VL,Ev
public synchronized int write(byte[] b,int nStart,int nLen) X5yhS
{ 3gh^a;uC
int n = -1; #P@r[VZ{6
try{ "|%fAE
oSavedFile.write(b,nStart,nLen); [aC9vEso!
n = nLen; ~zX5}U<R
} '[E_7$d
catch(IOException e) !58JK f
{ 4%7*tVG
e.printStackTrace (); n 3]y$wK
} =>J#_Pprn
<KA@A}
?C{N0?[P-
return n; ?n+\T'f!
} `ouzeu9}
OY#_0p)i
Ye6O!,R
} f5-={lUlIS
`!8Z"xD
]*h}sn=
/* 19t*THgq
**SiteInfoBean.java QMY4%uyY!
*/ *)1z-rH`
package NetFox; 3"n8B6
J_@4J7
hH/O2
public class SiteInfoBean { T1&H!
~] 2R+
hzb|:
private String sSiteURL; //Site's URL ;p ('cwU%
private String sFilePath; //Saved File's Path %R>S"
private String sFileName; //Saved File's Name {@%(0d{n}
private int nSplitter; //Count of Splited Downloading File nE;gM1I
mg(56)
^'4uTbxP_!
public SiteInfoBean() WU\bJ}
{//nSplitter的缺省值为5 &/F[kAy
//default value of nSplitter is 5 8|GpfW3p2
this("","","",5); $ZO<8|bW
} J.l%HU
bn35f<+
?g4|EV-56
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rp*t"HSaAW
{ eHe /w9`$R
sSiteURL= sURL; BaAb4{
sFilePath = sPath; Hrnql
sFileName = sName; \[EWxu
this.nSplitter = nSpiltter; \k_3IP?o=
uLljM{I
R <\Yg3m8
} NGUGN~p
y3]"H(
Q{hOn]"
public String getSSiteURL() MlE~gCD
{ ;%alZ
return sSiteURL; sLp LY1X
} Yj\yO(o/
2kq@*}ys
63Yu05'
public void setSSiteURL(String value) !\O,dq
{ U&$]?3?
sSiteURL = value; =Gz>ZWF
} "Cj#bUw
2z# @:Q
*+4iBpyiB
public String getSFilePath() Bqlc+d:
{ NV4W2thYo
return sFilePath; 89=JC[c
} }zxh:"#K
Jjh!/pWZ4
/ i2-h
public void setSFilePath(String value) F5[ITK]A4
{ +STzG/9#
sFilePath = value; B^~Bv!tHWr
} 3#9r4;&
p!QneeA`&X
k]9>V@C
public String getSFileName() /~cL L
{ G$9|aaf`1#
return sFileName; Rha3
} pbxcsA\
|0R%!v(,
6Ok=q:;
public void setSFileName(String value) V?dK*8s
{ H6S vU
sFileName = value; 7h&`BS
} V^/^OR4k
p<fgUVR
<O)X89dFM
public int getNSplitter() wK`ieHmp
{ NV(4wlh)y
return nSplitter; ::R00gd
} 3=|2Gs?ut
_JIUds5
n9fA!Wic
public void setNSplitter(int nCount) gIM'bA<~
{ 7RC096 ?}
nSplitter = nCount; }cK~=@7tK
} z<vO#
} \ jXN*A
O0(Q0Ko
.C;_4jE
/* zpr@!76
**Utility.java {!eANm'
*/ <eFAI}=s
package NetFox; DcR}pQ(e
l(w vQO
3?Eoj95w!
public class Utility { Ar7mH4M
$EGRaps{j>
V;hwAQbF
public Utility() ._MAHBx+G
{ j5h 6u,^:
SM#S/|.]
hn\Q6f+
} [aM'
.i&ZT}v3
//线程睡眠 u!3]RGJ
public static void sleep(int nSecond) =6:L+V
{ 'uf\.F
try{ 'tu@`7*
Thread.sleep(nSecond); !MJe+.
} Cq*}b4^;
catch(Exception e) I`'a'
{ H1%[\X?=
e.printStackTrace (); uQu/(5
} ^L-w(r62<
} ^2C /!Y<
w0j/\XN2s
//日志 T<f\*1~^
public static void log(String sMsg) !H1tBg]5
{ 8hKP
System.err.println(sMsg); RE>ks[
} JYg% ~tW'
LZc$:<J<6
?)' 2l6
public static void log(int sMsg) I!@s6tG
{ K4k~r!&OU
System.err.println(sMsg); z{@R.'BD
} h^A3 0f_x
} hH1lgc
*m$PH"
sCF40AoY&
/* R>d@tr
**TestMethod.java 2sqm7th
*/ ?AnjD8i
package NetFox; f{igW?Ho
^}o7*
\+iu@C
public class TestMethod { Gg9VS&VI
/}w#Jk4pD
2f|6z-Z
public TestMethod() 3$c(M99r
{ ///xx/weblogic60b2_win.exe SLtSqG7~
try{ s!#HZK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Re*|$r#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `l>93A
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8M^wuRn
fileFetch.start(); 0%s3Mp6H
} )RwBg8
catch(Exception e){e.printStackTrace ();} wfxOx$]zK
rQ
c[VrC+e m
} g ?afX1Sg
M[aT2A
Ys-Keyg
public static void main(String[] args) 8FzHNG
{ 5M%,N-P^
new TestMethod(); )n7|?@5U
} 'h-3V8m^e
} d5DP^u
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