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)); <2E|URo,#
} _U_O0@xi
for(int i=0;i<nEndPos.length-1;i++) !Ii[`H
{ hvGD`
nEndPos = nStartPos[i+1]; 31~nay15
} 9Pb6Z}
nEndPos[nEndPos.length-1] = nFileLength; Cz)&R^
} s+?2oPa
} gBky ZK
.g3=L
&7i&"TNptP
//启动子线程 %q}[ZD/HD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /w1M%10
for(int i=0;i<nStartPos.length;i++) E.Q]X]q
{ |AH>EXhv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :KgH7s}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DXo]O}VF
nStartPos,nEndPos,i); S,j. ?u*!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f S[-K?K
fileSplitterFetch.start(); &s(J:P$!
} =W &Mt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V2!0),]B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !~&&&85
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xeL"FzF:V
nEndPos = " + nFileLength); kU+|QBA@
// fileSplitterFetch[nPos.length-1].start(); Zwm/c]6`
H %c6I
lxm/*^
//等待子线程结束 j*5IRzK1%0
//int count = 0; cGiL9|k
//是否结束while循环 5f{P% x(
boolean breakWhile = false; :\vs kk),
cT(6>@9@
R{fJ"Q5'
while(!bStop) >MGWN
{ c}+*$DeT
write_nPos(); u4_QLf@I
Utility.sleep(500); M+0PEf.
breakWhile = true; \nt~K}a
+U1 Ir5Lx
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for(int i=0;i<nStartPos.length;i++) hbOXR.0z
{ Z4EmRa30 p
if(!fileSplitterFetch.bDownOver) veHe
{ w`;HwK$ ,
breakWhile = false; =C2sl;7~*
break; K Ax=C}9
} vjq2(I)u
} )Xh}N
if(breakWhile) o]~\u{o#.
break; -?-XO<I
h7E~I J
g"Y_!)X
//count++; fO$){(]^
//if(count>4) ICb!AsL
// siteStop(); v,S5C
} 58Ce>*~
ov,|`FdU^T
y-db CYMc
System.err.println("文件下载结束！"); {$,\Qg
} t|$jgM
catch(Exception e){e.printStackTrace ();} (Kwqa"Hk4{
} ~g\~x
aknIrblS\
&yvvea]
//获得文件长度 \4L ur
public long getFileSize() 0eNdKE
{ +bS\iw+
int nFileLength = -1; <@<bX
try{ ? Bpnnwx
URL url = new URL(siteInfoBean.getSSiteURL()); ts!tv6@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .P$m?p#
httpConnection.setRequestProperty("User-Agent","NetFox"); ]:Gy]qkO
4kjfYf@A
,\s`T O
int responseCode=httpConnection.getResponseCode(); E=N$JM
if(responseCode>=400) @QQ%09*
{ g#=<;X2
processErrorCode(responseCode); >I|8yqbfm
return -2; //-2 represent access is error st;iGg
} dMH_:jb
GLn=*Dh#
Tb$))O}
String sHeader; 3)y1q>CQf
1o`1W4Q
E ?Mgbd3
for(int i=1;;i++) rXi&8R[
{ [zx|3wWAX-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J5G<Y*q
//Utility.log(in.readLine()); '9zW#b
sHeader=httpConnection.getHeaderFieldKey(i); E.h
if(sHeader!=null) 0&UG=q
{ PjeI&@
if(sHeader.equals("Content-Length")) TKR#YJQ?K
{ $<v4c5r]O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {^z73Gxt,
break; 8YFG*HSa
} taE p
} . vb##D
else 6sBt6?_T
break; mol,iM*l
} zr/v.$<
} Y"H`+UV
catch(IOException e){e.printStackTrace ();} 1zPS#K/3
catch(Exception e){e.printStackTrace ();} 8>9Mh!t}(I
w.q`E@ T*
hzsQK_;S
Utility.log(nFileLength); 2iG+Ek-?"
)X0=z1$
MY,~leP&
return nFileLength; '4 *0Pw
} <= o<lRU
/_0B5,6R
?6CLUu|7n
//保存下载信息（文件指针位置） "E\vdhk
private void write_nPos() ,~Mf2Y#m0p
{ i1cd9
try{ 0vqVE]C
output = new DataOutputStream(new FileOutputStream(tmpFile)); J\y^T3Z
output.writeInt(nStartPos.length); mD'nF1o Ly
for(int i=0;i<nStartPos.length;i++) O>' }q/
{ .;4N:*hY
// output.writeLong(nPos); !T,<p
output.writeLong(fileSplitterFetch.nStartPos); x4I!f)8Q
output.writeLong(fileSplitterFetch.nEndPos); tnJ7m8JmC
} F9 r5 Z
output.close(); h9QM nH'
} wH ,PA:
catch(IOException e){e.printStackTrace ();} Pvc)-A
catch(Exception e){e.printStackTrace ();} gD9CA*
} !-lI<$S:
N;3!oo4
z}[u~P,
//读取保存的下载信息（文件指针位置） < o?ua}
private void read_nPos() R!M'
{ @D;K&:~|N
try{ \p(S4?I7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !, BJO3&
int nCount = input.readInt(); _<(xjWp 8
nStartPos = new long[nCount]; 2nyK'k
nEndPos = new long[nCount]; 28"1ONs3
for(int i=0;i<nStartPos.length;i++) VZi1b0k1.
{ v WXo#
nStartPos = input.readLong(); th{f|fm62
nEndPos = input.readLong(); G3_7e A#;
} tg\Nm7I
input.close(); GrLxERf
} lwQ!sH[M
catch(IOException e){e.printStackTrace ();} zDdo RK@
catch(Exception e){e.printStackTrace ();} B~I ]3f
} E{T3Xwg
P8YnKyI,.
LA6XTgcu
private void processErrorCode(int nErrorCode) Yh1</C
{ 6]1RxrAV
System.err.println("Error Code : " + nErrorCode); gX{j$]^6G8
} Q#%LIkeq
! v![K
b$'%)\('g
//停止文件下载 ^UvL1+
public void siteStop() ~!({Unt+'
{ 8WytvwB}
bStop = true; c +]r
for(int i=0;i<nStartPos.length;i++) I0F[Z\U
fileSplitterFetch.splitterStop(); ~T@E")uR
E<yQB39
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} fz|*Plv
} D9g*+KM&
//负责部分文件的抓取 2!6hB sEr
**FileSplitterFetch.java dEDhdF#f
*/ +PYV-@q
package NetFox; /(~ HHNnh
zu}uW,XH-
Vx!ZF+
import java.io.*; < dE7+w
import java.net.*; ck;:84
1O Ft}>1
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public class FileSplitterFetch extends Thread { #X)DFAtb
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&3iI\s[
String sURL; //File URL \*MZ1Q*x
long nStartPos; //File Snippet Start Position L"YQji!
long nEndPos; //File Snippet End Position <W!T+sMQj
int nThreadID; //Thread's ID \l=A2i7TQ
boolean bDownOver = false; //Downing is over vVBWhY]
boolean bStop = false; //Stop identical }!K #
FileAccessI fileAccessI = null; //File Access interface gX!K%qJBg
'{,JuX"n
H2],auBY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dU-:#QV6
{ QHv]7&^rlj
this.sURL = sURL; W _[9
this.nStartPos = nStart; S8v,'Cc
this.nEndPos = nEnd; ^X#)'\T
nThreadID = id; Zdrniae ah
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e[fld,s
} -d?<t}a
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public void run() 9vi+[3s/=;
{ :LuA6
while(nStartPos < nEndPos && !bStop) VN-0hw/A
{ 6U).vg<
MZ)lNU l
&kf \[|y
try{ |3k r*#
URL url = new URL(sURL); x6aVNH=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :2 \NG}
httpConnection.setRequestProperty("User-Agent","NetFox"); G$)q% b;Lz
String sProperty = "bytes="+nStartPos+"-"; HE*^!2f
httpConnection.setRequestProperty("RANGE",sProperty); bv7)[,i
Utility.log(sProperty); xz`0V}dPl
g1XpERsSEV
G9S3r3
InputStream input = httpConnection.getInputStream(); *[>{9V
//logResponseHead(httpConnection); 0]ai*\,W7~
sfVzVS[
E.C=VfBW
byte[] b = new byte[1024]; 1&h\\&ic
int nRead; Uvk:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "wVisL2+.
{ t^bh2$J
nStartPos += fileAccessI.write(b,0,nRead); iJZvVs',
//if(nThreadID == 1) :"Vmy.xq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); di;~$rI!?
} E\2f"s
%M_F/O
ybf,pDY#f
Utility.log("Thread " + nThreadID + " is over!"); pvWNiW:~k
bDownOver = true; ^!m%:r7Dr
//nPos = fileAccessI.write (b,0,nRead); l(MjLXw5
} pl}W|kW}
catch(Exception e){e.printStackTrace ();} Cf 202pF3y
} B8wGWZ@
} 5-4
VaonG]Ues
;Zf7|i`R3
//打印回应的头信息 ./tZ*sP:
public void logResponseHead(HttpURLConnection con) ga'G)d3oS
{ {#=o4~u%;H
for(int i=1;;i++) .Z`xNp
{ U4"&T,'lTL
String header=con.getHeaderFieldKey(i); )REegFN@
if(header!=null) /`qQWB5b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Gu(Yoa}y
Utility.log(header+" : "+con.getHeaderField(header)); "MPS&OK
else =g%<xCp
break; 8&hxU@T~
} AO-~dV
} aEEb1Y
P(\x. d:
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public void splitterStop() sCf)#6mI
{ ow+_g R-
bStop = true; &G-dxET]
} $;";i:H`
O*F= xG
N+]HJ`K
} 6 {`J I
FrRUAoFO
A(XX2f!i
/* }Oe4wEYN)
**FileAccess.java -g"Wi@Qr
*//文件访问(定位，写) >N0L
package NetFox; 1n)YCSA
import java.io.*; Bi/E{k,
Lm^vS u
V2yX;u
public class FileAccessI implements Serializable{ eOb)uIF
zo ]-,u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V\c`O
RandomAccessFile oSavedFile; IUG}Q7w5
long nPos; X2<fS~m
;+3@S`2r
/*6[Itm_h
public FileAccessI() throws IOException L8pKVr
{ |*~SR.[`
this("",0); (76tYt~I=
} nGDY::nUE
&`g^b^i
H-% B<7
public FileAccessI(String sName,long nPos) throws IOException WxJaE;`Ige
{ L'e|D=y
oSavedFile = new RandomAccessFile(sName,"rw"); Lq#!}QcW=
this.nPos = nPos; 8yswi[
oSavedFile.seek(nPos); hBDmC_\~
} 7?y([i\y
MbQ%'z6D
S2 -J1x2N
public synchronized int write(byte[] b,int nStart,int nLen) Q0XSQOl
{ nx!+:P ,
int n = -1; T#}"?A|
try{ GG4FS
oSavedFile.write(b,nStart,nLen); Jg&f.
n = nLen; U*BI/wZ
} $GD Q1&Z
catch(IOException e) u`*1OqU
{ 0\1g-kc!v
e.printStackTrace (); S""F58H n
} Gg^gK*D
pe!"!xJE
R$2\Xl@qQF
return n; i66/2BUh.
} SO`b+B
AgOti]`aR
C)cuy7<
} i2)$%M&
+WCV"m
L7yEgYB
/* i@=(Y~tD`
**SiteInfoBean.java Xk:_aJ
*/ a!&<jM
package NetFox; 0|mCk
BtF7P}:MGf
`nd$6i^#W
public class SiteInfoBean { s+0S,?{$
"Qk)EY
.sZ"|j9m
private String sSiteURL; //Site's URL Wm!cjGK
private String sFilePath; //Saved File's Path ZQsVSz( 1
private String sFileName; //Saved File's Name Bl+PJ 0
private int nSplitter; //Count of Splited Downloading File m*14n_m'
o#-^Lg&
^HWa owy=
public SiteInfoBean() .p78 \T
{//nSplitter的缺省值为5 4SIS#m
//default value of nSplitter is 5 ^aqBL
this("","","",5); q3u:Tpn4%
} k P=~L=cK
`cFNO:
g9F?j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iG{xDj{CKv
{ #a 4X*X.8c
sSiteURL= sURL; xeRoif\4c
sFilePath = sPath; SM.KM_%K
sFileName = sName; L}tP_ *
this.nSplitter = nSpiltter; I9sQPa
.bNG:y>
=GC,1WVEqV
} :f0#4'f
' $"RQ=
rrs0|=
public String getSSiteURL() pvdCiYo1r
{ 50Ov>(f@7
return sSiteURL; C|S~>4`
} `>HrO}x^
kq>I?wg
L1MG("R
public void setSSiteURL(String value) 3#{Al[jq
{ 3 t+1M
sSiteURL = value; V?n=yg
} 7J|nqr`>t
]4,eCT
z7HM/<WY
public String getSFilePath() ugs9>`fF&
{ L1QDA}6?_Y
return sFilePath; Eo0/cln|
} ~6#O5plKc
1-sG`%
O-n JuZJgX
public void setSFilePath(String value) !{b4+!@p
{ G^le91$
sFilePath = value; ,-SWrp`f
} \$xj>b;
AK&=/[U>
6P02=
public String getSFileName() PeJIa %iE
{ !WTL:dk
return sFileName; && b;Wr
} :c9 H2
X?'pcYSL
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public void setSFileName(String value) rw[Ioyr-
{ n]jw!;
sFileName = value; {n(/ c33
} IJDE{)
>LW}N!IBy
~P'i /*:
public int getNSplitter() qTe@?j
{ M[QQi2:&
return nSplitter; {=ATRwUL
} (P-$tHt
y N,grU(
@iN"]GFjS
public void setNSplitter(int nCount) HmbQL2
{ $#E!/vVwD7
nSplitter = nCount; N{uVh;_
} plM:7#eA
} ,OFNV|S$
yV*4|EkvW
m"wP]OQH*+
/* 5&0qr$
**Utility.java .Gb!mG
*/ Yw_!40`
package NetFox; sGc.;":
l_Zx'm
^ U~QQ
public class Utility { gmZ] E45
\85~~v@
664D5f#EJ
public Utility() /|isRh|
{ \J(kM,ZJ
s%1ZraMvJ
*NC@o*
} #@F.wV0
&_74h);2I:
//线程睡眠 ~yJJ00%
public static void sleep(int nSecond) w@LLxL>Y
{ :TkMS8
try{ e9>~mtx
Thread.sleep(nSecond); `UTUrM
} <(i5hmuVd
catch(Exception e) ^,aI2vC
{ "<LWz&e^^
e.printStackTrace (); Zpz3?VM(
} ilAhw4A
} d0;?GQYn:
V)P8w#,
//日志 <,\U,jU_
public static void log(String sMsg) ^9kx3Pw?8
{ 4eJR=h1
System.err.println(sMsg); L$,yEMCe
} W||&Xb
.eLd0{JtN
mv^X{T
public static void log(int sMsg) :[7O=[pk
{ o7@C$R_#
System.err.println(sMsg); zjOOEvi
} cQm4q19
} K~B
=}.gU WV
'xEK0~awD
/* IhOAMH1
**TestMethod.java ?:G 3U\M
*/ buT6)~lw
package NetFox; _n_()at)
AREjS$
s;$f6X
public class TestMethod { `46z D ?
+wf9!_'
5lM2nhlf'b
public TestMethod() Xj~%kPe
{ ///xx/weblogic60b2_win.exe ~S\> F\v6'
try{ ;#:AM;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -&=dl_m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); );kD0FO1|
SiteFileFetch fileFetch = new SiteFileFetch(bean); _*MK"
fileFetch.start(); EX#AJ>?V(
} ]Y!x7
catch(Exception e){e.printStackTrace ();} V:vqt@
!F.h+&^D;
PcqS#!t
} eTuKu(0 E
[FLR&=.(
I Zw
public static void main(String[] args) :q?#$?
{ e.~11bx
new TestMethod(); "%\hDL;
} 57-Hx;
} 2TNK
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