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)); @5?T]V g
} Q5,@P?
for(int i=0;i<nEndPos.length-1;i++) H;sQ]:.*]
{ R^B2J+O
nEndPos = nStartPos[i+1]; @i{JqHU"
} 3K?0PRg
nEndPos[nEndPos.length-1] = nFileLength; mzT} C&hfP
} )b%c]!
} "{x~j\<
K%pmE?%,8
"}OFwes
//启动子线程 q5vs;,_ |
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /2@%:b)
for(int i=0;i<nStartPos.length;i++) >|Jw,,uf
{ 4|$D.`Wu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0[1!K&(L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d(@A
nStartPos,nEndPos,i); +1)C&:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g?>AY2f[5
fileSplitterFetch.start(); /5x`TT
} r0X2cc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o`77gkLO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *}_/:\v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @zJI0_Bp
nEndPos = " + nFileLength); BL8\p_U
// fileSplitterFetch[nPos.length-1].start(); i`>X5Da5
k( g$_ ]X
7&At_l_
//等待子线程结束 sN C?o[9l!
//int count = 0; EkL\~^
//是否结束while循环 nUd\4;J#
boolean breakWhile = false; *b)b#p
`U g.c
6#KI? 6
while(!bStop) Dz50,*}J
{ *cf"l
write_nPos(); 8zc!g|5"
Utility.sleep(500); + kF[Oh#
breakWhile = true; Un/fP1
%b{!9-n}
^ Wl/
for(int i=0;i<nStartPos.length;i++) c}QJ-I
{ aqM_t
if(!fileSplitterFetch.bDownOver) !n{c#HfG
{ Yjl0Pz.q
breakWhile = false; }-L@AC/\#
break; 5{g9Wh[
} d_,tXV"z&
} m@,>d_|-K-
if(breakWhile) g\-3c=X
break; epbp9[`
=a!6EkX *
pMquu&Td
//count++; V1:3
//if(count>4) ]T51;j'48
// siteStop(); <kSaSW
} h]Oplp4\W
_B1uE2j9
"B}08C,?
System.err.println("文件下载结束！"); -*lP1Nbp
} {^f0RGJg9
catch(Exception e){e.printStackTrace ();} >Y+KL
} D9C}Dys
Cv~hU%1T
Qf|}%}%fp
//获得文件长度 1hviT&
public long getFileSize() VjqdKQeVq
{ S1zw'!O5
int nFileLength = -1; 4sj%:
try{ nwo!A3w:
URL url = new URL(siteInfoBean.getSSiteURL()); IA^)`l7H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7S2F^,w
httpConnection.setRequestProperty("User-Agent","NetFox"); |+:ZO5FaO
D%idlL2%J
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int responseCode=httpConnection.getResponseCode(); oPy zk7{
if(responseCode>=400) ]R{"=H'
{ +2}(]J=-
processErrorCode(responseCode); fE*I+pe
return -2; //-2 represent access is error | q16%6q
} \z`d}\3(R
8-5jr_*
mG~y8nUtp
String sHeader; qE72(#:R*
m[{&xF|_
DP_Pqn8p&M
for(int i=1;;i++) arLl8G[
{ (<C%5xk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6h_k`z
//Utility.log(in.readLine()); |<|,RI?
sHeader=httpConnection.getHeaderFieldKey(i); 0:Y`#0qK
if(sHeader!=null) <u?hdwW\
{ \.1b\\
if(sHeader.equals("Content-Length")) #@6L|$iX
{ c2\vG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )Zf}V0!?+
break; N#)VD\m
} $l;tP
} DiQkT R
else GQ0(&I
break; %B&?D@
} I*t)x,~3
} ~9 WJrRWB
catch(IOException e){e.printStackTrace ();} ,Q#tA|:8j
catch(Exception e){e.printStackTrace ();} '<=MhNh\
/C"s_:m;3
fF>qU-
Utility.log(nFileLength); YaZt+WA
I!7.fuO
W:poUG1UR
return nFileLength; /e sk
} K2rS[Kdfaq
z83:a)U
A4Q)YY9~
//保存下载信息（文件指针位置） 6+;2B<II
private void write_nPos() iB3+KR
{ !-RpRRR[Co
try{ %H}Y]D~R
output = new DataOutputStream(new FileOutputStream(tmpFile)); Mto~ /
output.writeInt(nStartPos.length); ^1,Eo2yN
for(int i=0;i<nStartPos.length;i++) `/JR}g{O
{ wwcwYPeg
// output.writeLong(nPos); b#;N!VX
output.writeLong(fileSplitterFetch.nStartPos); \Tf{ui
output.writeLong(fileSplitterFetch.nEndPos); UeQ9G
} D'[P,v;Q
output.close(); Df,VV+
} Px7g\[]
catch(IOException e){e.printStackTrace ();} .(dmuV9
catch(Exception e){e.printStackTrace ();} /9+A97{
} A Wh*<H
lcT+$4zk.
TnBGMI,g'
//读取保存的下载信息（文件指针位置） a H|OA\<
private void read_nPos() K@sP~('
{ _{`'{u
try{ )]b@eGNGj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K# i*9sM
int nCount = input.readInt(); NVA`t]gn
nStartPos = new long[nCount]; ):fu
nEndPos = new long[nCount]; {.D2ON
for(int i=0;i<nStartPos.length;i++) 0"<;You
{ %c&Ah
nStartPos = input.readLong(); )|h;J4V
nEndPos = input.readLong(); aHPSnB&
} uCP6;~Ns
input.close(); ,6orB}w?z
} LB*#
catch(IOException e){e.printStackTrace ();} )47j8jL
catch(Exception e){e.printStackTrace ();} =7]Q6h@X
} gjegzKU
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rI^~9Rz
private void processErrorCode(int nErrorCode) aC8,Y$>?E`
{ a,57`Ks+n<
System.err.println("Error Code : " + nErrorCode); &^3~=$
} enbN0
(LT\ IJSM
'q};L6
//停止文件下载 >uchF8)e|
public void siteStop() qtwT#z;Y
{ zsMw5C
bStop = true; Fy_<Ui
for(int i=0;i<nStartPos.length;i++) p[@oF5M
fileSplitterFetch.splitterStop(); _KM$u>B8
O^R:_vb3I
gKs/T'PW
} Q 9gFTLQ
} Gxh~
//负责部分文件的抓取 4j@kMe;RjZ
**FileSplitterFetch.java ySuLt@X
*/ V:F+HMBk
package NetFox; Ef_F#X0#
L=$?q/=-
93^(O8.
import java.io.*; Hc&uE3=%sL
import java.net.*; S QM(8*:X
<(bCz>o|
R%)2(\
public class FileSplitterFetch extends Thread { RlslF9f
@!&Jgg53G
Y( V3PnH
String sURL; //File URL LG Y!j_bD
long nStartPos; //File Snippet Start Position Qw6KX#n
long nEndPos; //File Snippet End Position p-i.ITRS
int nThreadID; //Thread's ID |auX*hb9
boolean bDownOver = false; //Downing is over I_zk'
boolean bStop = false; //Stop identical {+/ .5
FileAccessI fileAccessI = null; //File Access interface g]==!!^<D
$||ns@F+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nqurY62Ip
{ u>t|X}JH
this.sURL = sURL; @`IXu$Wm(
this.nStartPos = nStart; '!+P{
this.nEndPos = nEnd; 43{_Y]
nThreadID = id; PQU3s$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w;yiX<t<
} W?"2;](
kyRh k\X
S6Xb*6
public void run() yUD_w
{ ~}7$uW0ol
while(nStartPos < nEndPos && !bStop) }DDVGs[
{ 2xL!PR-
:_o] F
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try{ Q{.{#G
URL url = new URL(sURL); -'O Q-5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >/!7i3Ow-
httpConnection.setRequestProperty("User-Agent","NetFox"); 55>" R{q
String sProperty = "bytes="+nStartPos+"-"; 6Q.{llO
httpConnection.setRequestProperty("RANGE",sProperty); wO2V%v^bp
Utility.log(sProperty); ,c,Xd
RV0>-@/x
-~vl+L
InputStream input = httpConnection.getInputStream(); RjR&D?dc
//logResponseHead(httpConnection); C@TN5?Z
{[M0y*^64$
[)Z'N/;0
byte[] b = new byte[1024]; '!j #X_;
int nRead; .%x"t>]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?qd,>
{ i\kTm?BQZ
nStartPos += fileAccessI.write(b,0,nRead); QMXD9H0{
//if(nThreadID == 1) O8K@&V p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )K>Eniou
} 05l0B5'p
c N02roQl
B\=SAi
Utility.log("Thread " + nThreadID + " is over!"); tr6jh=
bDownOver = true; 3W7;f!
//nPos = fileAccessI.write (b,0,nRead); [+g(
} <mv7HKVg
catch(Exception e){e.printStackTrace ();} ZQ,fm`y\
} #dva0%-1
} ~w Zl2I
.-SDo"K.h
g ,/a6M
//打印回应的头信息 I! h(`
public void logResponseHead(HttpURLConnection con) 'O.+6`&
{ Zdv.PGn
for(int i=1;;i++) u-AWJc+F.
{ V,>+G6e
String header=con.getHeaderFieldKey(i); *'UhlFed
if(header!=null) 0K=Qf69Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5kGxhD
Utility.log(header+" : "+con.getHeaderField(header)); W4)kkJ
else 0Y2\n-`z
break; g\ErJ+i
} XIr{U5$<6
} 2Pbe~[
Q)x?B]b-
vOos*&
public void splitterStop() RL?u n}Qa
{ u] F70C^~
bStop = true; Ni+3b
} I#"t'=9H
zq,iLoY[R
iP<k1#k
} BQyvj\uJ
j y7
'M~BE\
/* Ze-MAt
**FileAccess.java NJn&>/vM
*//文件访问(定位，写) aQ(`6DQv
package NetFox; 7cIC&(h5
import java.io.*; iLF^%!:X%
uY.=4l
/SnynZ.q
public class FileAccessI implements Serializable{ /h/6&R0l
1|o$X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sCVI 2S!L
RandomAccessFile oSavedFile; ;*y|8od B
long nPos; <A)+|Y"^h6
Vo #:CB=8
jr9&.8%W:v
public FileAccessI() throws IOException Y8)}PWMs
{ _Ny8j~
this("",0); =kd YN5R
} ,5/V@;i
q.-y)C) ;
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public FileAccessI(String sName,long nPos) throws IOException ?Q@L-H`
{ `'uUmyg
oSavedFile = new RandomAccessFile(sName,"rw"); }ppVR$7]0
this.nPos = nPos; CV s8s
oSavedFile.seek(nPos); #MUiL=
} JxjP@nr
#:$O=@@?M
k]Zo-xh4
public synchronized int write(byte[] b,int nStart,int nLen) #;d)?
{ |</"N-#S
int n = -1; 6G'<[gL j
try{ 'g]hmE
oSavedFile.write(b,nStart,nLen); IQT cYl
n = nLen; 3=Z<wD s
} {] O`gG
catch(IOException e) ,:^ N[b
{ x Y| yI>
e.printStackTrace (); x;Gz6|
} IeVLn^?+:
JL.5QzA
NjbwGcH%\
return n; t)ld<9)eB
} !(Q l)C
nB=0T`vQ
NUMi])HkN
} 3@G;'|z
WE")xhV6
)%s +?
/* 9SY(EL
**SiteInfoBean.java cqEHYJ;B
*/ Xem 05%,
package NetFox; Kh)FyV
BBvZeG $Y
L!gDFZr
public class SiteInfoBean { jPnO@H1
z!:'V]
y?>#t^
private String sSiteURL; //Site's URL sMH#BCC
private String sFilePath; //Saved File's Path p'&*r2_ram
private String sFileName; //Saved File's Name aM$\#Cx
private int nSplitter; //Count of Splited Downloading File |1"!kA
6yI}1g
k,rWa
public SiteInfoBean() FSU<Y1|XM
{//nSplitter的缺省值为5 H>.B99vp
//default value of nSplitter is 5 >dk9f}7-
this("","","",5); ('t kZt%8
} >!}`%pk(
QsOhz
=Ey`M#t;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n>P!u71
{ M/{g(|{
sSiteURL= sURL; A:eG5K}
sFilePath = sPath; _R7 w?!t8
sFileName = sName; t}Ss=0dJO
this.nSplitter = nSpiltter; :mpiAs<%U"
=OYQM<q
W/r^ugDV
} I]X
cOkgoL" 4
oEu>}JD
public String getSSiteURL() h>wcT VF
{ m"Qq{p|'
return sSiteURL; ^mg*;8eGa
} [T`}yb@
3sFeP&
8Mu;U3cIW
public void setSSiteURL(String value) U<47WfcW
{ Pr+~Kif
sSiteURL = value; C c*({
} HR60
`5'2Hg+
M$A#I51
public String getSFilePath() &aPl`"j
{ %jEY3q
return sFilePath; <tbZj=*O/o
} i"HgvBHx
9cd8=][
K)S;:MLG=
public void setSFilePath(String value) z856 nl
{ >|3a 9S
sFilePath = value; 0@)%h&mD
} frN3S
Km3&N
DA"}A`HfI
public String getSFileName() @T&t.|`
{ @Z;1 g
return sFileName; F Z!J
} Y-p<qL|_
+;q.Y?
H9` f0(H
public void setSFileName(String value) xd8 *<,Wj
{ ~ y;y(4<
sFileName = value; jxw_*^w"
} R8&|+ya
<y)E>Fl
dTGA5c
public int getNSplitter() 7zDiHac
{ = .oHnMX2M
return nSplitter; *Oo &}oAj
} }nud
k\N4@UK
A+ 0,i
public void setNSplitter(int nCount) E'c%d[:H,
{ ;=jr0\|e
nSplitter = nCount; 1f4bt6[
} ;/LD)$_
} u+D[_yd^
x*}bo))hb
}!)F9r@\
/* 8]< f$3.
**Utility.java DjHp+TyT
*/ 8)xt(~qF
package NetFox; ~rv})4h
$/_qE
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public class Utility { cDV^8 R
#Hu~}zy
Ip?]K*sq
public Utility() op7FZHs
{ UG2w 1xqHw
N4UM82N
9z ?7{2C
} K:5eek
u&]vd /
//线程睡眠 TJy4<rb
public static void sleep(int nSecond) }$gmK
{ *t9eZ!_f?
try{ [!"XcFY:a
Thread.sleep(nSecond); QH@>icAb
} .px:e)iW
catch(Exception e) onte&Ed\
{ )`HA::
e.printStackTrace (); Vhg1/EgUr
} mBk5+KyT
} 0ys~2Y!eH
1 W'F3
//日志 oq;'eM1,.
public static void log(String sMsg) YaY8 `M{
{ Bjj<\8^M
System.err.println(sMsg); UUtbD&\
} <I=$ry6 8
cHD%{xlb
Bw<rp-
public static void log(int sMsg) Z1,gtl ?
{ Hs0pW5oZ
System.err.println(sMsg); >q7 %UK]&
} 68t}w^=
} {3edTu
.~klG&>aV
;D2E_!N dt
/* B|o%_:]+E
**TestMethod.java >a>fb|r
*/ {0yu
package NetFox; Xm_$ dZ
B0)]s<<
`M@Ak2gcR+
public class TestMethod { Y2T$BJJ
kA#vByf`v
6*XM7'n
public TestMethod() LSd*|3E}n
{ ///xx/weblogic60b2_win.exe 8cVzFFQP
try{ 5EeDHsvV9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [}o~PN:sT(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k%Vv?{g
SiteFileFetch fileFetch = new SiteFileFetch(bean); g-)mav
fileFetch.start(); n2ndjE$
} 0SV\{]2
catch(Exception e){e.printStackTrace ();} ` 2%6V)s
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K"{HseN{
} J|QiH<
%mI~ =^za
*\XH+/]+
public static void main(String[] args) RtV.d\
{ rT7^-B*
new TestMethod(); Un@\kAY
} "{BqtU*.
} xJ(:m<z
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