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)); PQ1\b-I
} .Zo8KwkFY
for(int i=0;i<nEndPos.length-1;i++) D{c`H}/`
{ ibEQ52
nEndPos = nStartPos[i+1]; q")}vN
} ^"l4
nEndPos[nEndPos.length-1] = nFileLength; I"r*p?
} HJwj,SL
} |ONkRxr@!
hMdsR,Iq
OD{Rh(Id
//启动子线程 ] OR]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A07FjT5w8
for(int i=0;i<nStartPos.length;i++) 9"&HxyOfX
{ )abo5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f.Jz]WXw,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wF}/7b54
nStartPos,nEndPos,i); y;uk|#qnPS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w_6h $"^x
fileSplitterFetch.start(); !YCYmxw#
} L[D}pL=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !x[+rf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^*RmT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q_JES4ofx
nEndPos = " + nFileLength); evq*&.6\
// fileSplitterFetch[nPos.length-1].start(); j`(o\Fd )
Nn+leM
>!?u8^C
//等待子线程结束 +tl&Jjdm
//int count = 0; PbCXcs
//是否结束while循环 T~_+\w
boolean breakWhile = false; )0YMi!&j`
cSQvP.
'xhX\?mD
while(!bStop) 4k}u`8 a
{ *SLv$A
write_nPos(); VcA87*pel
Utility.sleep(500); Q@nxGm
breakWhile = true; 1jO/"d.8n
Za5*HCo
Gw$U0HA[,
for(int i=0;i<nStartPos.length;i++) 5)nm6sf
{ 1:XT r
if(!fileSplitterFetch.bDownOver) $yBU ,lu}
{ .(ki(8Z N
breakWhile = false; S+7>Y? B!
break; (Jy7
} /(5SJ(a
} 7C F-?M!
if(breakWhile) ?FxxH*>"
break; ["kk.*&
uveTx
*q\Ve)E}
//count++; FlttqQQdf
//if(count>4) /V^Gn;
// siteStop(); b~z1%?
} ,aU_bve
<%Bsb}h,
9Y3_.qa(.
System.err.println("文件下载结束！"); c\065#f!
} ^/U-(4O05*
catch(Exception e){e.printStackTrace ();} UzWf_r
} r1}YN<+,s
W^Wr
=bi:<%"
//获得文件长度 TkM8GK-3
public long getFileSize() q]DV49UK
{ :D""c*
int nFileLength = -1; i]JD::P_H
try{ c=0S]_
URL url = new URL(siteInfoBean.getSSiteURL()); mR)Xq=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VE`5bD+%e
httpConnection.setRequestProperty("User-Agent","NetFox"); nn5tOV}QE
eF823cH2x_
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int responseCode=httpConnection.getResponseCode(); R%=u<O
if(responseCode>=400) >,yE;zuw
{ tt$DWmm
processErrorCode(responseCode); V>>"nf,YO
return -2; //-2 represent access is error ,6uON@
} |#^wYZO1U
T@ (MSgp9
@FKm_q
String sHeader; Z%E;*R2+:>
4V@raI-
n6Je5fE
for(int i=1;;i++) i 3?=up!
{ dkVF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dDK4I3a
//Utility.log(in.readLine()); W2?6f:
sHeader=httpConnection.getHeaderFieldKey(i); /zJDQ'k0
if(sHeader!=null) US[{ Q
{ l 8qCg/ew
if(sHeader.equals("Content-Length")) O~?H\2S
{ .76T<j_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QpxRYv
break; % put=I
} >slD.rb]
} P MV;A{T
else Xn@\p5<
break; hLK5s1#K
} "%ou'\}
} @-qS[bV
catch(IOException e){e.printStackTrace ();} O9?t,1
catch(Exception e){e.printStackTrace ();} A/ZZ[B-
`K5Lp>=R
+GqK$B(x7
Utility.log(nFileLength); 'Z5l'Ac
b&BkT%aA(G
?y_W%ogW
return nFileLength; \]uD"Jqv#
} #}Y$+FtO
&\),V1"
BPs|qb-
//保存下载信息（文件指针位置） zW.I7Z0^
private void write_nPos() N1/)Fk-z
{ Gmi ^2?Z(
try{ #[ZToE4
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zq1ZrwPF
output.writeInt(nStartPos.length); B?n 6o|8
for(int i=0;i<nStartPos.length;i++) O=m_P}K
{ v%a)nv
// output.writeLong(nPos); @D1}).
output.writeLong(fileSplitterFetch.nStartPos); pn"TFapJA
output.writeLong(fileSplitterFetch.nEndPos); Sp/t[\,'
} %EV\nwn6
output.close(); \vwsRT 1
} eYNu78u
catch(IOException e){e.printStackTrace ();} 6bPoC$<Z
catch(Exception e){e.printStackTrace ();} w1U2cbCr/
} ~C M%WvS
w(Jf;[o
bvn%E H
//读取保存的下载信息（文件指针位置） X?'ShXI
private void read_nPos() rG[iEY
{ }\ kLh(
try{ LL% Aw)Q`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1'Sr0 oEd3
int nCount = input.readInt(); 5\!t!FL_
nStartPos = new long[nCount]; n1!hfu7@s
nEndPos = new long[nCount]; NSs"I]
for(int i=0;i<nStartPos.length;i++) v\lhbpk
{ Hreu3N
nStartPos = input.readLong(); Yx#?lA2gx
nEndPos = input.readLong(); R%Xhdcn7
} ={~?O&Jh
input.close(); X;:qnnO
} :)JIKP%$\)
catch(IOException e){e.printStackTrace ();} 2:[ -
catch(Exception e){e.printStackTrace ();} J:D{5sE<|
} [7Fx#o=da
Y6W#uiqk
U)v){g3w)
private void processErrorCode(int nErrorCode) ?`T0zpC
{ +|0f7RB+R
System.err.println("Error Code : " + nErrorCode); IkWV|E
} oyw*Z_9~
X%X`o%AqC
=:fN
//停止文件下载 U~3uu&/r
public void siteStop() >;qAj!'
{ Q' b@5o
bStop = true; }^Ymg7wA
for(int i=0;i<nStartPos.length;i++) /FJ.W<hw
fileSplitterFetch.splitterStop(); qe/dWJBa
LOO<)XFJ
E^s<5BC;
} o,NTIh
} ccR#<Pb6q
//负责部分文件的抓取 kz!CxI (
**FileSplitterFetch.java 9Gh:s6
*/ L/Tsq=
package NetFox; 3bsuE^,.@
b;;mhu[D
6Dl]d%.
import java.io.*; C\`*_t
import java.net.*; |(eRv?Qy@
U3t$h
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public class FileSplitterFetch extends Thread { ob.Br:x
&0`[R*S
W^e"()d/Z
String sURL; //File URL PP*',D3
long nStartPos; //File Snippet Start Position 0%(.$c>:f
long nEndPos; //File Snippet End Position Qr.SPNUFK
int nThreadID; //Thread's ID Uf,fd
boolean bDownOver = false; //Downing is over OK]_.v}
boolean bStop = false; //Stop identical rbt/b0ET
FileAccessI fileAccessI = null; //File Access interface DYf3>xh>xb
6lAHB*`
'G)UIjl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F[@M?
{ 90Sp(
this.sURL = sURL; 0FAe5 BE7
this.nStartPos = nStart; < C1Jim
this.nEndPos = nEnd; [,a2A
nThreadID = id; dy' J~Eo7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1 !8 b9
} X~2L
t,]E5,1
xg.o7-^M
public void run() .P:mYC
{ w<|Qezi3 w
while(nStartPos < nEndPos && !bStop) Z1dLC'/b]
{ Spm0DqqR?
}!_ofe
7Zw.mM!i
try{ 2kfX_RK
URL url = new URL(sURL); bXNM.K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #S|DoeFs
httpConnection.setRequestProperty("User-Agent","NetFox"); o%SD\zk
String sProperty = "bytes="+nStartPos+"-"; X,mqQ7+
httpConnection.setRequestProperty("RANGE",sProperty); 4:0y\M5u
Utility.log(sProperty); Vh}F#~BrI
SJ8CBxA
B:]%Iu|
InputStream input = httpConnection.getInputStream(); PZ.q
//logResponseHead(httpConnection); &:?2IAe
A(@VjXl
`#3FvP@&
byte[] b = new byte[1024]; ozOvpi:k3%
int nRead; O<>cuW(l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @%b&(x^UD
{ (:r80:
nStartPos += fileAccessI.write(b,0,nRead); kSUpEV+/
//if(nThreadID == 1) !(i}FFn{:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NpAZuISD!
} _I/uW|>
[XbNZ6
2tqj]i
Utility.log("Thread " + nThreadID + " is over!"); CzfGb4
bDownOver = true; |r<#>~*
//nPos = fileAccessI.write (b,0,nRead); %1Nank!Zj
} 7 (kC|q\4M
catch(Exception e){e.printStackTrace ();} _O;2.M%@
} hdN[wC]
} 231,v,X[
vp4NH]fJ
^~DDl$NH
//打印回应的头信息 #`o]{UfW
public void logResponseHead(HttpURLConnection con) I3hN7
{ = P@j*ix
for(int i=1;;i++) |y$8!*S~(
{ | k?r1dj%O
String header=con.getHeaderFieldKey(i); i$gH{wn\`
if(header!=null) ]t)#,'$^[W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `|`Qrv4}
Utility.log(header+" : "+con.getHeaderField(header)); ,a'Y^[4k?
else J^gElp
break; v[XTH 2
} |PxTm
} fq<JX5DER
s ;2ih)[
U+ANSW/
public void splitterStop() .^!<cFkCE
{ TsF>Y""*M
bStop = true; UfSqiu
} TjY-C m
fP8iz `n
rv<_'yj
} T=,A pa
^-2|T__
M]7>Ar'zsG
/* %U?1Gf e
**FileAccess.java G7NRpr
*//文件访问(定位，写) q+{$"s9v
package NetFox; .C\##
import java.io.*; cH48)
b]6@ O8
g:eqB&&
public class FileAccessI implements Serializable{ jz$ ]"\G#
;!(GwgllD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9/#?]LJ
RandomAccessFile oSavedFile; Xy]Pmt
long nPos; yvIzgwN%s!
P$#{a2
]114\JE
public FileAccessI() throws IOException !g7lJ\B
{ 1LVO0lT
this("",0); zff<#yK1
} QWI)Y:<K/
s"JD,gm$
0Zh]n;S3m
public FileAccessI(String sName,long nPos) throws IOException \e9rXh%
{ d#1yVdqRl
oSavedFile = new RandomAccessFile(sName,"rw"); SIZZFihcYh
this.nPos = nPos; Fk#$@^c@
oSavedFile.seek(nPos); 4Kh0evZ
} >/.w80<'
#?C.%kD
2y5d
public synchronized int write(byte[] b,int nStart,int nLen) mX5%6{],
{ ;~-M$a }4
int n = -1; B+2EIaI
try{ @hwe
oSavedFile.write(b,nStart,nLen); )skz_a}]8
n = nLen; BcxALRWE
} "cz'|z`
catch(IOException e) n?:%>Os$
{ * zt?y
e.printStackTrace (); Q N]y.(S)y
} A/!"+Yfw
ps_q3Cyp
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return n; CB^.N>'
} 2 9#jKh
N?2C*|%f
u';9zk/$
} 26ae|2?
722:2 {
j;BlpRD}
/* \l1==,wk
**SiteInfoBean.java 1ne3CA=
*/ 0k G\9
package NetFox; yT-qT_.
a4&Aw7"X
CUnBi?Mi
public class SiteInfoBean { b\S~uFq6
|B {*so]
*RM 3_
private String sSiteURL; //Site's URL L6./5`bs
private String sFilePath; //Saved File's Path h+ <Jv
private String sFileName; //Saved File's Name s#H_QOE
private int nSplitter; //Count of Splited Downloading File N6HeZB":
qLV3Y?S!L
VWK%6Ye0
public SiteInfoBean() $wC'qV *
{//nSplitter的缺省值为5 FfNUFx2N
//default value of nSplitter is 5 &%`WXe-`R
this("","","",5); X?U'GLm
} yA#nnu1
8n35lI( [
C6'K)P[p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e'MW"uCP}
{ o Vpq*"
sSiteURL= sURL; qTSe_Re
sFilePath = sPath; m/3,;P.6
sFileName = sName; 66-tNy
this.nSplitter = nSpiltter; `|2g&Vn
14DhJUV"b
c~+KrWbZ~
} )=VAEQhL-
L'w]O -86
2ZEDyQM
public String getSSiteURL() bXSAZWf
{ @'<=EAXe
return sSiteURL; qrf90F)
} szCB}WY
dNf:I,<DCf
)|/%]@` N
public void setSSiteURL(String value) g`C\pdX"B
{ V8#NXUg<!
sSiteURL = value; [HI$[:[
} U!(es0rX
_2Mpzv
U C_$5~8p
public String getSFilePath() GvZ[3GT
{ pxn@rN#*
return sFilePath; !;;7:!)P
} < 0YoZSNGj
f]_'icP
0xY</S
public void setSFilePath(String value) fejC,H4I
{ 9Dbbk/j|
sFilePath = value; }3_>
} 7"F29\
a7685Y
CeeAw_*@
public String getSFileName() mV^~
{ b:cy(6G(
return sFileName; BOWOH
} %/ctt_p0x
*`8JJs0g
loC~wm%Ql
public void setSFileName(String value) D^gS.X^
{ [X91nUz#
sFileName = value; wh)F&@6 R!
} Y::O*I2
je5[.VTM
:a^/&LbLm
public int getNSplitter() q}!h(-y}5n
{ 80ox$U
return nSplitter; ,Ha<lU2K
} SF`(`h0e
|s;']
l))Q/8H
public void setNSplitter(int nCount) \VA*3U^@
{ D*j^f7ab
nSplitter = nCount; #IJeq0TVB
} S@g(kIo]
} tcO{CI
~Hu!iZ2]
]T'7+5w
/* T2 S fBs
**Utility.java VFzIBgJ3
*/ p!5'#\^f
package NetFox; [(gXjt-
;s;3cC!
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public class Utility { bAbR0)
#f<v%
u`&lTJgF/O
public Utility() #y[U2s Se
{ YM};85K
T@Y, 7ccpd
yYaoA/0
} ""Da2Md
;1s+1G}_z
//线程睡眠 z:@:B:E
public static void sleep(int nSecond) {}$Zff
{ Zazff@O *
try{ P#,;)HF
Thread.sleep(nSecond); *yaS^k\
} 0y6M;"&~E
catch(Exception e) &!OEd]
{ *ziR&Fr!
e.printStackTrace (); yIrJaS-
} Zk`yd8C
} 'E+"N'M|
o<G#%9j
//日志 "VZXi_P
public static void log(String sMsg) u*TC8!n
{ N+h05`
System.err.println(sMsg); l?=\9y
} D}q"^"#T
"4;nnq
_'LZf=V0
public static void log(int sMsg) -(t7>s
{ pF4Z4?W
System.err.println(sMsg); ;8eKAh
} __2<v?\
} P RWb6
Qr9;CVW
y TD4![
/* fT|A^
**TestMethod.java UXs)$
*/ xC,x_:R`
package NetFox; bh<;px-
Vv45w#w;
KWZhCS?[(
public class TestMethod { 3iIy_nWC
REU,"
3f] ;y<Km
public TestMethod() pK@=]K~l0
{ ///xx/weblogic60b2_win.exe USEb} M`
try{ j/z=<jA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?%h$deJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 68Gywk3]=u
SiteFileFetch fileFetch = new SiteFileFetch(bean); _ i}W1i
fileFetch.start(); l2qvYNMw
} N,c!1:b
catch(Exception e){e.printStackTrace ();} Aj)Q#Fd[
xwf-kwF8^
nUOi~cs
} L%T(H<G
.VCY|KZ
pA6KiY&
public static void main(String[] args) EUi 70h+
{ V}Y*Yv
new TestMethod(); E4L?4>V@\
} ]7O<|8n!d
} W&IG,7tr
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