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)); "^E/N},%u5
} 9l).L L
for(int i=0;i<nEndPos.length-1;i++) }%(e`[?1
{ 7L~LpB
nEndPos = nStartPos[i+1]; %"tLs%"7=P
} w{uqy]
nEndPos[nEndPos.length-1] = nFileLength; /*3[9,
} @V{s'V
} 62lG,y_L
HDqPqrWm
^.bYLF
//启动子线程 5sJi- ^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pw:(X0@
for(int i=0;i<nStartPos.length;i++) Hik8u!#P
{ fy|ycWW>8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Q!qJav
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3`sM/BoA
nStartPos,nEndPos,i); /3|uU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wq&|V
fileSplitterFetch.start(); [pMJ9 d$
} xbJ@z{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `H+~LVH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _22;hnG<iy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", me]O
nEndPos = " + nFileLength); Z-(#}(HD
// fileSplitterFetch[nPos.length-1].start(); Uw R,U#d
DVCO( fz
}#~@HM>6Z
//等待子线程结束 6<0-GD}M
//int count = 0; +g36,!q
//是否结束while循环 2q}M1-^
boolean breakWhile = false; _4qP0LCa
=Gsn4>~%n
vqh@)B+)
while(!bStop) v_Om3i9$E
{ +zodkB~)
write_nPos(); K"'W4bO#7
Utility.sleep(500); &8!*u3
breakWhile = true; ERxA79
_Eq*
=hE5 ?}EP+
for(int i=0;i<nStartPos.length;i++) Gy{C*m7Q
{ }'HJVB_
if(!fileSplitterFetch.bDownOver) :%GxU;<E{
{ oXw}K((|
breakWhile = false; d"zbY\`
break; uv*OiB"
} "0Xa?z8"
} Bi?.w5
if(breakWhile) cU}j Whu
break; l!Q |]-.@
[s?H3yQ.
A#9@OWV5f
//count++; C6Qnn@waYb
//if(count>4) \ZdV|23
// siteStop(); LF+#PnK
} n99>oh
bni :B?#
u@d`$]/>F
System.err.println("文件下载结束！"); Hbogi1!al|
} 0gNwC~IA8
catch(Exception e){e.printStackTrace ();} I}oxwc
} K{[ySB
dRg1I=|{_
,aI 6P-
//获得文件长度 #;. tVo I
public long getFileSize() uS :3Yo
{ G'c!82;,?
int nFileLength = -1; ]p3hq1u3&
try{ $LUNA.
URL url = new URL(siteInfoBean.getSSiteURL()); h>B>t/k?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =x "N0p
httpConnection.setRequestProperty("User-Agent","NetFox"); 2!QS&i
?_9cFo59:
/|] %0B
int responseCode=httpConnection.getResponseCode(); :CEhc7gU
if(responseCode>=400) ;6aTt2BQ
{ "kyy>H9)
processErrorCode(responseCode); (:3rANY|
return -2; //-2 represent access is error |6LC>'
} Ve>*KHDSt
=L~,HS(l,
@]lKQZ^2&
String sHeader; .E:QZH'M
?! dp0<
Zab5"JR
for(int i=1;;i++) Zcd!y9]#
{ s+?r4t3H!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pE>~F
//Utility.log(in.readLine()); e#`wshtN:
sHeader=httpConnection.getHeaderFieldKey(i); T1m097
if(sHeader!=null) !Dp4uE:Pq
{ 061@N=p8
if(sHeader.equals("Content-Length")) nIVPh99
{ `+]9+:tS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !?B9 0(
break; fx|$(D@9
} l= 5kd.{
} R{S{N2+p(
else M@@"-dy
break; bG nBV7b
} 2GECcx53
} c0ET]
catch(IOException e){e.printStackTrace ();} K V^`
catch(Exception e){e.printStackTrace ();} hnS ~r4
$oK,&_
Vf6lu)Zc1
Utility.log(nFileLength); mJb>)bOl
"PGEiLY
==I:>+_^|
return nFileLength; DV +DJcF
} #9z\Wblr
u#XNl":x
b8)>:F
//保存下载信息（文件指针位置） }S'+Ytea
private void write_nPos() 5o\yhYS:
{ En3Q%
try{ Fc>W]1
output = new DataOutputStream(new FileOutputStream(tmpFile)); :av6*&+
output.writeInt(nStartPos.length); c_a*{L|c
for(int i=0;i<nStartPos.length;i++) ]od]S8$5
{ g':mM*j&
// output.writeLong(nPos); P7d" E
output.writeLong(fileSplitterFetch.nStartPos); dix\hqZ
output.writeLong(fileSplitterFetch.nEndPos); 3EB8ls2
} ,eD@)K_:
output.close(); "_jczr$*
} ]qL#/
catch(IOException e){e.printStackTrace ();} cl{x5>.'#
catch(Exception e){e.printStackTrace ();} yNdtq\h
} _7.Wz7]b
Sai_rNRWB
oz%ZEi\bW
//读取保存的下载信息（文件指针位置） "XMTj <D
private void read_nPos() Zeyhr\T
{ {c|nIwdB
try{ 5~4I.+~8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dsqqq,>Q
int nCount = input.readInt(); jy{T=Nb
nStartPos = new long[nCount]; x, a[ p\1
nEndPos = new long[nCount]; hu[=9#''$
for(int i=0;i<nStartPos.length;i++) <9eQ
{ ],R rk]1
nStartPos = input.readLong(); [qlq&?"
nEndPos = input.readLong(); mIq6\c$
} vV.'&."g
input.close(); punc'~
} \tLJ( <8
catch(IOException e){e.printStackTrace ();} @5Q}o3.zA-
catch(Exception e){e.printStackTrace ();} i%>]$*
} .z7XYmv
wIuwq>
XLp tJ4~v
private void processErrorCode(int nErrorCode) f]q3E[?/
{ $ t_s7
System.err.println("Error Code : " + nErrorCode); s@ m A\
} j,eeQ KH
i}ypEp
sLzcTGa2:z
//停止文件下载 t*y4)I !gR
public void siteStop() Qpiv,n
{ wcP0PfY
bStop = true; |ap{+ xh
for(int i=0;i<nStartPos.length;i++) uF9p:FvN8
fileSplitterFetch.splitterStop(); ]oP2T:A
U#1T HO`
`zRgP#
} ja70w:ja
} MX6*waQ-<
//负责部分文件的抓取 +jO1?:Lr
**FileSplitterFetch.java J7t5B}}
*/ #*#4vMk<
package NetFox; +[`N|x<
)mxY]W+
Ki}PO`s
import java.io.*; }qT @.
import java.net.*; lYT}Nc4"="
CjORL'3
75wQH*
public class FileSplitterFetch extends Thread { `rW{zQYM
:+ @-F>Q
h1G]w/.ws
String sURL; //File URL Y}'C'PR
long nStartPos; //File Snippet Start Position Df02#493
long nEndPos; //File Snippet End Position zC!]bWsD
int nThreadID; //Thread's ID z|F>+6l"Y7
boolean bDownOver = false; //Downing is over tc\LK_@$/F
boolean bStop = false; //Stop identical j{>E.F2.
FileAccessI fileAccessI = null; //File Access interface FIlw
Fp+^`;j
+cM;d4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &1893#V
{ (\.[pj%-O
this.sURL = sURL; [yL%+I
this.nStartPos = nStart; <%<}];bmFL
this.nEndPos = nEnd; +|r;t
nThreadID = id; lYv :
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fo&q/;l\
} !0c7nzjm
.\X/o!xC
zA9N<0[]o
public void run() 6(B0gBCId
{ [=u8$5/a
while(nStartPos < nEndPos && !bStop) Q#urx^aw
{ `r'q(M
"v/^nH
+`u]LOAyP=
try{ r-'\<d(J$
URL url = new URL(sURL); sn2SDHY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?`AzgM[I
httpConnection.setRequestProperty("User-Agent","NetFox"); 2,/("lV@0
String sProperty = "bytes="+nStartPos+"-"; f'\I52;FB
httpConnection.setRequestProperty("RANGE",sProperty); {}N*e"<O
Utility.log(sProperty); wJ1qJ!s@
9 }|Bs=q
oiJa1X
InputStream input = httpConnection.getInputStream(); (<s7X$(]e
//logResponseHead(httpConnection); R+P,kD?
%Ub"V\1
$%`OJf*k
byte[] b = new byte[1024]; )9##mUt'}
int nRead; dP T)&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f|WNPFQ$x
{ JVwYV5-O<0
nStartPos += fileAccessI.write(b,0,nRead); E0\ '
//if(nThreadID == 1) 8<0H(lj7_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E,shTh%&~
} \yNjsG@,
x^8xz5:O
I?J$";A
Utility.log("Thread " + nThreadID + " is over!"); rl'YyO}2
bDownOver = true; 91E!4t}I
//nPos = fileAccessI.write (b,0,nRead); e%`gD*8
} VvSD&r^qI
catch(Exception e){e.printStackTrace ();} })T}e7>T
} ]2QZ47
} o B_c6]K
3%{XJV
|Q`}a %
//打印回应的头信息 LT!.M m
public void logResponseHead(HttpURLConnection con) -5>K pgXo\
{ PDREwBX
for(int i=1;;i++) H&[CSc
{ A;1<P5lo
String header=con.getHeaderFieldKey(i); gEIjG
if(header!=null) I"#jSazk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [X#bDO<t
Utility.log(header+" : "+con.getHeaderField(header)); =+T{!+|6P
else -9}]J\
break; ~bL(mq
} ,(N&%
} (03m%\
"^;'.~@e8
bd_U%0)pi1
public void splitterStop() :(} {uG
{ }di)4=U9
bStop = true; QKCc5
} jeN_ sm81b
j,/OzVm9
w:r0>
} SLSJn))@!
L q'*B9
?#ndMv!$
/* ZL#4X*zT
**FileAccess.java \s`'3y
*//文件访问(定位，写) #?}k0Y
package NetFox; yf*MG&}
import java.io.*; ~)tIO<$U
Pw1V1v&>q
$7jJV(B
public class FileAccessI implements Serializable{ (+4gq6b
zc'!a"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )+RGXVp
RandomAccessFile oSavedFile; cm%QV?
long nPos; Q {3"&
@'?<92A
_T6WA&;8
public FileAccessI() throws IOException [`=|^2n?
{ ?:s`}b
this("",0); zbddn4bW9
} 5Jp@n .
{ogGi/8
VHM,W]
public FileAccessI(String sName,long nPos) throws IOException |n=m8X
{ p!AQ
oSavedFile = new RandomAccessFile(sName,"rw"); 2!~j(_TA
this.nPos = nPos; 2etcSU(y>
oSavedFile.seek(nPos); &1F)/$,v
} Q6_!I42Y`
ul(1)q^
OC#oJwC
public synchronized int write(byte[] b,int nStart,int nLen) k^ B'W{
{ 4sSQ nK
int n = -1; !Lb9KDk
try{ Kk!D|NKLC
oSavedFile.write(b,nStart,nLen); t.j q]L
n = nLen; J*.Nf)i
} kej@,8
catch(IOException e) Rr^<Q:#"<|
{ I=x
e.printStackTrace (); 8niQG']
} }z,4IHNn
B:n9*<v(
$A7[?Ai ?
return n; ='pssdB
} -[~{c]/c
pA!+;Y!ZB<
|5F]y"Nb
} []1VD#
rD%(*|Y"c
CP7Zin1S/w
/* AXH4jQw
**SiteInfoBean.java ]QtdT8~
*/ xHJ+!
package NetFox; /6gqpzum4
)KaQ\WJ:
Zu$f-_"
public class SiteInfoBean { /!eC;qp;[
{3$ge
}qmZ
private String sSiteURL; //Site's URL ?)",}XL6
private String sFilePath; //Saved File's Path R{8nR00|1
private String sFileName; //Saved File's Name 3`n5[RV
private int nSplitter; //Count of Splited Downloading File 3+{hO@O
}Da8S|)H
9gn_\!Mp
public SiteInfoBean() CYEqH2"3
{//nSplitter的缺省值为5 UQPd@IVu6
//default value of nSplitter is 5 aPcO9
this("","","",5); $$A{|4,aI
} y`mEsj
hNyYk(t^
@xtcjB9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L G,XhN
{ =Q.2:*d.
sSiteURL= sURL; gEO#-tMjOQ
sFilePath = sPath; l#~Sh3@L(
sFileName = sName; {u9(qd;;
this.nSplitter = nSpiltter; fF_1ZKx+#!
kkyn>Wxv
NX@TWBn%
} .m;1V6
WQv~<]1JF
qOZc}J0
public String getSSiteURL() 8s?;<6
{ nvu|V3B0
return sSiteURL; Ny*M{}E
} (FH4\'t)
3yr{B Xn
uEVRk9nb
public void setSSiteURL(String value) m1]rLeeEt
{ JI3AR e?y
sSiteURL = value; &ad9VB7
} .#5<ZAh/?
M4nM%qRGQ
v_{`O'#j^
public String getSFilePath() '}P)iS2
{ =H>rX 2k
return sFilePath; #MHnJ
} _UjAct]6
u<!!%C~+=
<C+:hsS=
public void setSFilePath(String value) &^63*x;hE
{ e~'y%|D
sFilePath = value; 2i |wQU5w
} 9{70l539
/-^gK^
WE|L{
public String getSFileName() fS1N(RZ1
{ ~<Gs<c}z
return sFileName; 9s73mu`Twg
} R(k6S
z;#}uC
u\^<V)
public void setSFileName(String value) Iy8gQdI
{ K?-K<3]9f
sFileName = value; 45/f}kvy
} O5Yk=-_m
c*~/[:}
7R7g$
public int getNSplitter() Te$/[`<U
{ S &s7]
return nSplitter; lH:TE=|4
} Z:O24{ro5
7fI[yCh
kzJNdYtdH
public void setNSplitter(int nCount) 6}C4 SZ
{ %[lX H
nSplitter = nCount; `q7I;w+g
} 9@QP?=\Y
} (z ;=3S
H!Uy4L~>
2?QIK3"v
/* #Sb1oLC
**Utility.java v}xz`]MW<,
*/ AJt0l|F
package NetFox; y"e'Gg2
wMt?yc:X
Y)c9]1qly
public class Utility { X]C-y,r[M
kul&m|
6by5VESx
public Utility() lCWk)m8
{ w gATfygr
^CZn<$
;?=] ffa{
} iP|h];a+@
Va(R*38k
//线程睡眠 B*Hp
public static void sleep(int nSecond) k/?+jb
{ % eW>IN]5
try{ N(t1?R/e,
Thread.sleep(nSecond); swi|
} ;o%r{:lng
catch(Exception e) 0RtqqNFD
{ 4K0N$9pd:
e.printStackTrace (); >W.Pg`'D
} B964#4& 9
} >I]t|RT])
Z7k {7
//日志 5y}}?6n+
public static void log(String sMsg) "JJ )w0
{ aODOc J N
System.err.println(sMsg); |;OM,U2
} ZN%$k-2
?Q9/C|
:'1ePq
public static void log(int sMsg) hJhdHy=U
{ FK@rZP
System.err.println(sMsg); ?*[t'D9f-
} wd..{j0&
} 9Hlu%R
hd/5*C{s
9p2"5x
/* ,8+SQo#3
**TestMethod.java p8Lb*7W
*/ )"t=sFxaB
package NetFox; _)2NFq
wC@4`h\U
:ozHuHJ#
public class TestMethod { D~NH 4B
>^n'
f`/JY!uj{
public TestMethod() ;P5\EJo
{ ///xx/weblogic60b2_win.exe saU|.\l
try{ H'?Bx>X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -("79v>#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?ohLcz
SiteFileFetch fileFetch = new SiteFileFetch(bean); jY87NHg
fileFetch.start(); 1ww|km
} &vdGKYs 6
catch(Exception e){e.printStackTrace ();} p7zHP
:Gy .P
;Jv)J3y
} V)!Oss;i
=!{}:An1$
UupQ*,dJ
public static void main(String[] args) )c]GgPH
{ Gp@Y=mU
new TestMethod(); 1MfRFv
} YCw^u
} MZv&$KG4m@
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