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)); 'MEO?]Tf.^
} 5~WMb6/
for(int i=0;i<nEndPos.length-1;i++) Mk-C&#'
{ oe1Dm
nEndPos = nStartPos[i+1]; "],amJ
} {. r/tV5IH
nEndPos[nEndPos.length-1] = nFileLength; Y)%CxaO`
} lZ^UAFF
} q*Xp"yBTo
(+g!~MP
\]AsL&
//启动子线程 r{~K8!=oU]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z`b.~<P
for(int i=0;i<nStartPos.length;i++) E3N4(V\*
{ LGb.>O^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~O{sOl _<4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,^JP0Vc*
nStartPos,nEndPos,i); (0%0+vY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mUi|vq)`=D
fileSplitterFetch.start(); M5OH-'
} l\l\T<wa,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), maANxSzi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h%kB>E~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a.F6!?
nEndPos = " + nFileLength); 54 8w v
// fileSplitterFetch[nPos.length-1].start(); H9)$ #r6i
#mqz*=L3
^=)? a;V
//等待子线程结束 o5+N_5OE}E
//int count = 0; B1@c`BJ;9T
//是否结束while循环 [ @>8Qhw
boolean breakWhile = false; !:3NPjhf1Y
*(&,&$1K
A0*u(15%
while(!bStop) ]2Aqqy
{ ;F@dN,Y
write_nPos(); DBi3 j
Utility.sleep(500); * wN+Ak q
breakWhile = true; UP:+1Sp9
&libC>a[
3"'|Ql.H
for(int i=0;i<nStartPos.length;i++) ]3#_BL)M8p
{ U[~BW[[@f
if(!fileSplitterFetch.bDownOver) ~..h=
{ tZ1iaYbvV
breakWhile = false; wxPg*R+t
break; <_""4
} 7I4G:-V:^
} hIa@JEIt
if(breakWhile) ,2?"W8,
break; DSix(bs9
7<{Zq8)
6<A\U/
//count++; )|/t}|DIx
//if(count>4) /= P!9d {
// siteStop(); <R~(6krJwZ
} ,<zZKR_
ja2LQe@Q
GpF,=:
System.err.println("文件下载结束！"); >fo &H_a
} VIbm%b$~
catch(Exception e){e.printStackTrace ();} F!{N4X>%T
} *n?6x!A
;3'}(_n
u7`<m.\
//获得文件长度 #v-)Ie\F?
public long getFileSize() 0t7yK
{ Jg k@ti.}Z
int nFileLength = -1; yB}y'5
try{ X4i$,$C
URL url = new URL(siteInfoBean.getSSiteURL()); N|q:wyS|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vzaxi;S<
httpConnection.setRequestProperty("User-Agent","NetFox"); fE)+9!
s4SR6hBO
vE?qF9I{$0
int responseCode=httpConnection.getResponseCode(); ?Z!itB~
if(responseCode>=400) R|t.wawCo
{ 5n.4>yOY
processErrorCode(responseCode); D]b5*_CT
return -2; //-2 represent access is error 0*:]eM};P
} 1`_Mc ]
f%*-PW^*
aI|)m8>)X
String sHeader; )." zBc#
ika{>hbH
>~J_9'gX6
for(int i=1;;i++) 4)9X) Qx
{ SVXey?A;CJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x#dJH9NR[
//Utility.log(in.readLine()); @R}L 4
sHeader=httpConnection.getHeaderFieldKey(i); Q+G=f
if(sHeader!=null) 7"4|`y^#
{ iO#H_&L.p
if(sHeader.equals("Content-Length")) "_'9KBd!
{ @oYq.baHX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n2,b~S\e
break; L6$,<}l
} 1Sz5&jz
} v}[KVwse
else xNxIqq<k
break; %XGX(
} @b!fs
} WF-imI:EK
catch(IOException e){e.printStackTrace ();} RWTv,pLK
catch(Exception e){e.printStackTrace ();} hPFIf>%}
w/G5I )G
KU33P>a"[k
Utility.log(nFileLength); .:RoD?px
[Z Ea3/
Bb:jy!jq_
return nFileLength; *N'B(j/
} ?\\ ]u
h"%6tpV-
>)N,V;j
//保存下载信息（文件指针位置） L/nz95
private void write_nPos() ;p\rgam
{ L1)?5D
try{ >R!^aJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); L?KEe>;r
output.writeInt(nStartPos.length); E pM 4+
for(int i=0;i<nStartPos.length;i++) !h9 An
{ 6xz&Qi7w
// output.writeLong(nPos); F w{8MQ2
output.writeLong(fileSplitterFetch.nStartPos); Zb2 B5(0
output.writeLong(fileSplitterFetch.nEndPos); SCxzT}#J
} <;9vwSH>
output.close(); b@,=;Y)O
} wK#UFOp
catch(IOException e){e.printStackTrace ();} 8n~@Rj5
catch(Exception e){e.printStackTrace ();} ,5r 2!d
} D"1ciO8^I]
]]%C\Ryy}
0TA/ExJ-LT
//读取保存的下载信息（文件指针位置） nsgNIE{>gO
private void read_nPos() Vp5qul%
{ I8^z\ef&
try{ j-{WPJa4\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T/S-}|fhQ
int nCount = input.readInt(); ,u]kZ]
nStartPos = new long[nCount]; J_P2%b=C
nEndPos = new long[nCount]; 4TR:bQZs
for(int i=0;i<nStartPos.length;i++) 6dq U4
{ )sNtwSl^
nStartPos = input.readLong(); U?|s/U
nEndPos = input.readLong(); (Z`Y
} N;[w`d'#
input.close(); +}9%Duim
} yxA0#6so
catch(IOException e){e.printStackTrace ();} 5@ZD'
catch(Exception e){e.printStackTrace ();} X#eVw|
} Pi*,&D>{7
b:%>TPT
/h2`?~k+
private void processErrorCode(int nErrorCode) O4$: xjs
{ u%*;gu"2
System.err.println("Error Code : " + nErrorCode); 'inWV* P*g
} I/^Lr_\
?'_iqg3
m?B@VDZ
//停止文件下载 ?+Qbr$]
public void siteStop() (x=NA )
{ Mu:*(P/
bStop = true; #lVVSrF,-
for(int i=0;i<nStartPos.length;i++) kP;Rts8JD
fileSplitterFetch.splitterStop(); z5Nw+#m| i
D]oS R7h
54}s:[O
} 'm/b+9?.
} CB|z{(&N
//负责部分文件的抓取 FP9ZOoog
**FileSplitterFetch.java ]i$CE|~
*/ J::SFu=
package NetFox; q(uu;l[
QT-rb~
N+}yw4lb
import java.io.*; 3rR(>}:[V
import java.net.*; 2,_BO6 !d
n!tCz<v
{h@R\bU
public class FileSplitterFetch extends Thread { Q6vkqu5!=
5Vvy:<.la
,:z@Ji
String sURL; //File URL y5R6/*;N.
long nStartPos; //File Snippet Start Position hUlFP
long nEndPos; //File Snippet End Position g" M1HxlV
int nThreadID; //Thread's ID yr;oq(&N
boolean bDownOver = false; //Downing is over /D~ ,X48+
boolean bStop = false; //Stop identical +pjD{S~Y
FileAccessI fileAccessI = null; //File Access interface ,g\.C+.S
,%ajIs"Gi
'-v~HwC+/T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #4"\\
{ fk",YtS*
this.sURL = sURL; mX2Qf8
this.nStartPos = nStart; ;2X1qw>
this.nEndPos = nEnd; xSLN
nThreadID = id; wL%>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zizrc.g/Yg
} 74Kl!A
WnIh( 0
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public void run() 1[}VyP6 e
{ @7BH`b$)!
while(nStartPos < nEndPos && !bStop) ~^3B(feQ]
{ f8uVk|a
^R2:Z&Iv%
4QDF%#~q^
try{ =RQ>q
URL url = new URL(sURL); K):)bL(B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m*a0V
httpConnection.setRequestProperty("User-Agent","NetFox"); e1'_]
String sProperty = "bytes="+nStartPos+"-"; rP>5OLP
httpConnection.setRequestProperty("RANGE",sProperty); ^Nc\D7( l
Utility.log(sProperty); 4Q!*h8O
Ig9$ PP+3
nq$^}L3&~
InputStream input = httpConnection.getInputStream(); L:%h]-
//logResponseHead(httpConnection); *J%+zH
f:BW{Cij;y
WS,p}:yPZG
byte[] b = new byte[1024]; r\em-%:
int nRead; _e?(Gs0BM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;>YJ}:r"\
{ sa*hoL18
nStartPos += fileAccessI.write(b,0,nRead); 9vVYZ}HC
//if(nThreadID == 1) z1YC%Y|R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8cW]jm
} &d~6MSk
@s@r5uR9B
UHxXa*HyI
Utility.log("Thread " + nThreadID + " is over!"); e+&/Tq'2
bDownOver = true; aFl(K\
//nPos = fileAccessI.write (b,0,nRead); EnfSVG8kB8
} 2P]rJ
catch(Exception e){e.printStackTrace ();} fw-LZ][
} Pw+cpM8<
} 7DT9\BT
3tgct <"
tF=96u_X
//打印回应的头信息 -o=qYkyLK
public void logResponseHead(HttpURLConnection con) 1o.]"~0:
{ = [:ruE
for(int i=1;;i++) t/nu/yz5E
{ 1 "4AS_Q
String header=con.getHeaderFieldKey(i); 2.2 s>?\
if(header!=null) |qZ4h7wL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Aw >DZ2
Utility.log(header+" : "+con.getHeaderField(header)); K{"+eA>CU
else `+i<:,z-gs
break; U${dWxC
} &:Raf5G-E
} /y NU0/
4S+P]U*jW
sdrE4-zd
public void splitterStop() QhN5t/Hr
{ Knn$<!>
bStop = true; M<Eg<*
} Wny{qj)=
?HU(0Vgn'
?n[+0a:8E
} UXe@c@3
%/~Sq?f-9@
&Tl3\T0D
/* ;B!&( 50e
**FileAccess.java [{'` |
*//文件访问(定位，写) X$J
package NetFox; d+z8^$z"
import java.io.*; OCF=)#}qd
a^|mF# z
UKn>.,
public class FileAccessI implements Serializable{ Dy0RZF4_
i?||R|>;"'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5Vf#(r f
RandomAccessFile oSavedFile; 8BBuYY{
long nPos; !~PV\DQN
vr2tMD
wR\%tumk
public FileAccessI() throws IOException Z+FJ cvYx
{ [N.4i" Cd
this("",0); FzW7MW>\x
} 1XL^Zhr
MT}9T
a$"3T
public FileAccessI(String sName,long nPos) throws IOException w8$8P
{ qK,rT*5=
oSavedFile = new RandomAccessFile(sName,"rw"); sF f@>
this.nPos = nPos; lg~Gkd6
oSavedFile.seek(nPos); -PoW56
} _-^a8F>/19
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Jro)
public synchronized int write(byte[] b,int nStart,int nLen) 8FU8E2zo
{ }cEcoi<v!
int n = -1; =J<3B H^m
try{ c7,p5[
oSavedFile.write(b,nStart,nLen); Qne@Vf kA
n = nLen; bRfac/:}
} o4\\q66K
catch(IOException e) yIA-+# r[
{ _-$(=`8|<{
e.printStackTrace (); iTwb#Q=
} _?CyKk\I
>-0Rq[)
;y/&p d+
return n; f;x0Ho5C2
} fX2sjfk
#Ipi3
@j=:V!g2O
} _h6SW2:z!E
"A6m-xE~
QVJq%P
/* ,` 6O{Z~
**SiteInfoBean.java 2Jo|]>nl}u
*/ "m4._4U
package NetFox; <Z5-?wgf9
j4k\5~yzS
";yey]
public class SiteInfoBean { u0zF::
qHaH=g%
@IhC:Yc
private String sSiteURL; //Site's URL lE'3UqK
private String sFilePath; //Saved File's Path z{`K_s%5
private String sFileName; //Saved File's Name JuQwZ]3ed
private int nSplitter; //Count of Splited Downloading File _wH>h$E
VkdGGY
VddHK
public SiteInfoBean() iO+,U}&
{//nSplitter的缺省值为5 ,sI<AFI
//default value of nSplitter is 5 x{4{.s%+:
this("","","",5); WX6}@mS.
} G!dx)v
fG9 ;7KG
`%;Hj _X}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KW-GVe%8f
{ /oOZ>B%1s
sSiteURL= sURL; {ppzg`G\
sFilePath = sPath; ,.9k)\/V
sFileName = sName; BX\/Am11
this.nSplitter = nSpiltter; ~I6N6T Z
j 5}'*
+`,;tz=?
} `>)[UG!:|
2Pow-o*r
)G#mC0?PV
public String getSSiteURL() /|q.q
{ ;NU-\<Q{
return sSiteURL; `6$|d,m5
} )Zf1%h~0r
0vX4v)-^u
xt_:R~/[
public void setSSiteURL(String value) aD]! eP/)
{ wg%g(FO
sSiteURL = value; i/j53towe
} CRBj>
Z<^;Ybw{`Z
w=pr?jt1:
public String getSFilePath() 'X<4";$mU
{ Q2/65$nW
return sFilePath; /sfJ:KP0
} ])}a^]0q
.7]P-]uOZ
o?Aj6fNY?
public void setSFilePath(String value) Z1#u&oX
{ 2ah%,o
sFilePath = value; Mg#yl\v
} T/a=z
4-~Z{#-
&rGB58
public String getSFileName() KL9k9|!p
{ fIl;qGz85
return sFileName; WQ{[q" O
} gg>QXui
(+c1.h
],_+J*
public void setSFileName(String value) )/?H]o$NU
{ Aa=:AkrH
sFileName = value; AdVc1v&>
} 6<2H 7'
9w$m\nV
=:aJZ[UU<2
public int getNSplitter() w lH\w?
{ T'9ZR,{F
return nSplitter; m>%b4M
} !$A/.;0$
4qdoF_
XEQTTD<
public void setNSplitter(int nCount) ;-6-DEL
{ Wl |5EY
nSplitter = nCount; #~!"`B?#*
} 3V<@Vkf5
} |~r-VV(=
T5 (|{-
tLBtE!J$[
/* =A.$~9P
**Utility.java Y8zTw`:V
*/ )rq |t9kix
package NetFox; >~SS^I0
r/2= nE
5?lc%,-&
public class Utility { -~mgct5
$#q`Y+;L2
#L~i|(=U5
public Utility() &)Xc'RQ.C
{ n:,mo}?X
e"ehH#i
=5q<_as
} d=/0A\O
vd{QFJ
//线程睡眠 9<6q(]U
public static void sleep(int nSecond) ovdJ[bO
{ hbJ>GSoZ,
try{ z5kAf~A
Thread.sleep(nSecond); g w" \pD
} N-gYamlQ
catch(Exception e) u.|Z3=?VG
{ 6RnzT d
e.printStackTrace (); g1s%x=7/
} #;$]M4
} xWxc1tT`
93>4n\
//日志 Qc; kj
public static void log(String sMsg) x@t?7 o\&
{ u= NLR\
System.err.println(sMsg); Ax;=Zh<DAv
} 1z?}'&:
9af.t
<Dd>- K
public static void log(int sMsg) +!/ATR%Uci
{ Y()"2CCV
System.err.println(sMsg); f8Iddm#
} p+CUYo(
} iRzFA!wH
TmsIyDcD~
/|IPBU 5
/* vrkY7L3\
**TestMethod.java /ad9Q~nJ
*/ `Mnu<)v
package NetFox; rmiOeS`:
=~B"8@B
CMXF[X)%
public class TestMethod { 9;E=w+
q,vWu(.
uM-,}7f7
public TestMethod() XBQt:7[<
{ ///xx/weblogic60b2_win.exe nlwqSXw
try{ xu2KEwgb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S/nPK,^d2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `*C=R _
SiteFileFetch fileFetch = new SiteFileFetch(bean); +$h
fileFetch.start(); [_,as
} ~HZdIPcC
catch(Exception e){e.printStackTrace ();} 5*AXL.2ih
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4:`D3
} D 2X_Yv
xN1P#
P{TJ$
public static void main(String[] args) cHs3:F~~
{ 8xAV[i
new TestMethod(); Mo,&h?VOM?
} U1[)eD`
} Lo%n{*if
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