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)); 3rX40>Cs8
} yJMo/!DZ
for(int i=0;i<nEndPos.length-1;i++) O)D$UG\<
{ wV\G$|Y
nEndPos = nStartPos[i+1]; #44}Snz
} j{6O:d6([$
nEndPos[nEndPos.length-1] = nFileLength; e@iz`~[
} h=^UMat-
} Q=Liy@/+!
NdrR+t^#
gH*(1*
//启动子线程 ^DVryeLD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rp|A88Q/!
for(int i=0;i<nStartPos.length;i++) zR)/h
{ h.kjJF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I= a?z<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^fmuBe}d{
nStartPos,nEndPos,i); t<"%m)J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~i!I6d~
fileSplitterFetch.start(); M>xT\
} G++<r7;x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /T+%q#4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '*^9'=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $F NH:r<
nEndPos = " + nFileLength); J"$U$.W=
// fileSplitterFetch[nPos.length-1].start(); PcjeuJZ
M{SJ8+G
b1QHZY\g{
//等待子线程结束 =Aw`0
//int count = 0; ?Ezy0>j
//是否结束while循环 m#4h5_N
boolean breakWhile = false; BqUwvB4
G ]uz$V6!
KtArV
while(!bStop) /:"^,i\t
{ ~+V$0Q;L
write_nPos(); |~&cTDd
Utility.sleep(500); 5.D0 1?k
breakWhile = true; mq(-L
|<O^M q
7P]i|Q{
for(int i=0;i<nStartPos.length;i++) h B_p
{ yr?X.Np
if(!fileSplitterFetch.bDownOver) Z#D*HAd`
{ T Qx<lw
breakWhile = false; ~z")';I|
break; 1Zi` \N4T
} Y*{5'q+2
} DLD9
if(breakWhile) (!qfd Qq#
break; H!Dj.]T
9c[bhGD?
%oWG"u
//count++; ,~DKU*A_~
//if(count>4) '=xO?2U-Z
// siteStop(); kD7'BP/#
} ,H8M.hbsQ
W;os4'h$
ovdaK"q2
System.err.println("文件下载结束！"); s,AJR [
} xxr'g =
catch(Exception e){e.printStackTrace ();} IO]tO[P#
} d|)ARRW
fEiNHVx
3Bvz& `\
//获得文件长度 s,kY12<7m
public long getFileSize() qg|ark*1u
{ S)W?W}*R\
int nFileLength = -1; yeBfzKI{b
try{ 94|ZY}8|f
URL url = new URL(siteInfoBean.getSSiteURL()); "]Uj _d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a>9_#_hI
httpConnection.setRequestProperty("User-Agent","NetFox"); QDVSFGwr
4\k{E-x $
D:?"Rf{)
int responseCode=httpConnection.getResponseCode(); .726^2sx
if(responseCode>=400) RlbJ4`a
{ 7i'clB9!
processErrorCode(responseCode); >n(dyU@
return -2; //-2 represent access is error %M/L/_d
} w=: c7Y+
i)$+#N
nEW.Y33
String sHeader; '.8eLN
m-+>h:1b|9
?^MH:o
for(int i=1;;i++) nh80"Ny5
{ 6ecx!uc$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Uovna:"
//Utility.log(in.readLine()); gg8)oc+w
sHeader=httpConnection.getHeaderFieldKey(i); @g]+$Yj
if(sHeader!=null) /u`Opv&I
{ kmo#jITa`
if(sHeader.equals("Content-Length")) Ag*?>I
{ [+#k+*1*o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pgq(yPC
break; 6W3."};
} m=/HUt3(&0
} `[XH=-p
else Ov4 [gHy&
break; HZS.%+2
} ~m0=YAlk?
} R/Sm
catch(IOException e){e.printStackTrace ();} nD>X?yz2
catch(Exception e){e.printStackTrace ();} 6 OvH"/X4
ZCb@!V}=
yd'cLZd<}
Utility.log(nFileLength); =knLkbiq7,
'O9Yu{M
B}*\ pdJ
return nFileLength; +l!.<:sp
} T nyLVIP
s?nj@:4
-em3 #V
//保存下载信息（文件指针位置） s>WqVuXmn
private void write_nPos() TaKHr$h
{ kkj@!1q(wO
try{ YnDaBpx
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2t
output.writeInt(nStartPos.length); I\rjw$V#
for(int i=0;i<nStartPos.length;i++) K:Z,4Y
{ ~7Nqwwx
// output.writeLong(nPos); k<f0moxs'
output.writeLong(fileSplitterFetch.nStartPos); ;eO Ye3;c
output.writeLong(fileSplitterFetch.nEndPos); h"}F3E
} 3W.D^^)eCV
output.close(); i12G\Ye
} Gz8JOl
catch(IOException e){e.printStackTrace ();} Y2N$&]O{
catch(Exception e){e.printStackTrace ();} e(`r"RrQ
} qEdY]t
73tjDO7d
/^&$ma\
//读取保存的下载信息（文件指针位置） 4K4u]"1
private void read_nPos() Ls.g\Gl3
{ rfZg
try{ |BGzdBm^x:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kjQI=:i=
int nCount = input.readInt(); 09G]t1!,
nStartPos = new long[nCount]; K+yi_n L
nEndPos = new long[nCount]; *S4&V<W>
for(int i=0;i<nStartPos.length;i++) o5Knot)Oy
{ P5"B7>L:
nStartPos = input.readLong(); m^)\P?M5|
nEndPos = input.readLong(); i@<w"yNd_
} D6e<1W
input.close(); e+@.n
} Ag1nxV1M$
catch(IOException e){e.printStackTrace ();} kll,^A
catch(Exception e){e.printStackTrace ();} MUN:}S
} u/\Ipk/
~H]d9C
"DJ%Yo
private void processErrorCode(int nErrorCode) [FWB
{ DFGgyFay
System.err.println("Error Code : " + nErrorCode); kYd=DY
} 1;>RK
;{n*F=%uC
lPlJL`e
//停止文件下载 \nQEvcH
public void siteStop() ,l\D@<F
{ V<REcII.
bStop = true; W*4!A\K
for(int i=0;i<nStartPos.length;i++) D[Ld=e8t
fileSplitterFetch.splitterStop(); fK=vLcH
\l 3M\$oS>
"M]`>eixL
} ,z0E2
} ? 5hwz
//负责部分文件的抓取 IRI<no
**FileSplitterFetch.java A?c?(~9O
*/ H329P*P
package NetFox; .:, 9Tf
W8!8/IZbN
KV'-^\
import java.io.*; yXc@i)9w3
import java.net.*; _LZ 442
+Nka,C^O"
h^b=
public class FileSplitterFetch extends Thread { KhbbGdmfS$
]}AyDy6C
c-a;nAR
String sURL; //File URL :#W>lq@H
long nStartPos; //File Snippet Start Position 8L(KdDY
long nEndPos; //File Snippet End Position R~BW=Dz,e
int nThreadID; //Thread's ID hzX&BI
boolean bDownOver = false; //Downing is over Xc]Q_70O
boolean bStop = false; //Stop identical ;V1e>?3
FileAccessI fileAccessI = null; //File Access interface e9?y0vT//
yAVt[+0
%] 7.E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z[_Gg8e
{ *yA.D?
this.sURL = sURL; H\e<fi%Q
this.nStartPos = nStart; :y[tZ&*<_?
this.nEndPos = nEnd; px_%5^zRQ
nThreadID = id; z3-AYQ.H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MT@Uu
} fBt7#Tc=U
Tk4"qGC.
}L*cP;m#
public void run() ,cFp5tV$
{ FKB)o7
while(nStartPos < nEndPos && !bStop) zL3'',Ha
{ ZCVN+::Y
.c.#V:XZ#U
U z6XQskX
try{ qT L@N9
URL url = new URL(sURL); .{W)E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T/C1x9=?
httpConnection.setRequestProperty("User-Agent","NetFox"); Zx]"2U#
String sProperty = "bytes="+nStartPos+"-"; wA}+E)x/C
httpConnection.setRequestProperty("RANGE",sProperty); DavG=kvd
Utility.log(sProperty); VIxcyp0X
z '%Vy
"2bCq]I0
InputStream input = httpConnection.getInputStream(); ]={{$}8.
//logResponseHead(httpConnection); 8~|PZ,oZ
dGzZ_Vf
^T|~L<A3
byte[] b = new byte[1024]; ABp/uJI)
int nRead; vH#^|u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b=+'i
{ f"5vpU^5*
nStartPos += fileAccessI.write(b,0,nRead); pJ5Sxgv{;
//if(nThreadID == 1) Ol24A^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U{o0Posg
} `=Hh5;ep
6F3#Rxh
( Qw"^lE3
Utility.log("Thread " + nThreadID + " is over!"); Y75,{1\l0
bDownOver = true; LdAfY0
//nPos = fileAccessI.write (b,0,nRead); T!)v9L
} ~V"D|U;i +
catch(Exception e){e.printStackTrace ();} GKwm %A
} 7PZ0
} _S#uxgL<
x,z+l-y
>_]j{}~\k
//打印回应的头信息 ;%AK< RT
public void logResponseHead(HttpURLConnection con) p/xxoU
{ ND7 gxt-B
for(int i=1;;i++) F%x8y
{ g#1_`gK
String header=con.getHeaderFieldKey(i); X/TuiKe
if(header!=null) {ls$#a+d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z!m0nx
Utility.log(header+" : "+con.getHeaderField(header)); Z*QsDS
else V3-5:z
break; =LS?:Mhm
} ZO+c-!%[(
} EOjo>w>
2hl'mRW
|b52JF ",
public void splitterStop() )G0a72
{ $z]gy]F
bStop = true; keEyE;O}u
} m0W5Ogk
}r6SV%]:
t7("geN]
} ` IiAtS
U&|=dH]-
j9sf~}D>
/* # &o3[.)9
**FileAccess.java z1?7}9~`0c
*//文件访问(定位，写) AW4N#gt8',
package NetFox; AxUj CerNf
import java.io.*; ;GO>#yg4Eh
JGp~A#H&
~fn2B
public class FileAccessI implements Serializable{ iK1<4)
(CS"s+y1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LZV
RandomAccessFile oSavedFile; a5:Q%F<!
long nPos; BDyOX6
<*~vZT i(
Slcf=
public FileAccessI() throws IOException $$2\qN -
{ c$Js<[1
this("",0); J (Yfup
} EX7cjQsml
0n|op:]BHM
^wCjMi(sj
public FileAccessI(String sName,long nPos) throws IOException .HF+JHIUu
{ 7\'vSHIL
oSavedFile = new RandomAccessFile(sName,"rw"); 900#K
this.nPos = nPos; a;D{P`%n
oSavedFile.seek(nPos); Glcl7f"<^
} IL?3>$,
=xWZJ:UnU
/Ou`$2H87
public synchronized int write(byte[] b,int nStart,int nLen) 1+v&SU
{ jzSh|a9_
int n = -1; Xy:'f".M~\
try{ ;(fDR8
oSavedFile.write(b,nStart,nLen); \@vR*E
n = nLen; 2?58=i%b
} ,5HQHo@
catch(IOException e) rY_)N^B|nF
{ ilEWxr;,
e.printStackTrace (); nellN}jYsM
} :2{6Pa(eg
U0q{8 "Pl
EFu2&P
return n; S)of.Nq.;
} l9"0Wu@_x
H%> E6rVB
\:-#,( .V
} E1usxF)
xV[X#.3
F0W4B
/* \:9dt8(-U
**SiteInfoBean.java 0]?} kY
*/ #'fh'$5"
package NetFox; G?CaCleG
%yX?4T;b
b}< T<
public class SiteInfoBean { 1Y4=D
16ahU$@-
"{1`~pDj?
private String sSiteURL; //Site's URL 6MQ+![fN
private String sFilePath; //Saved File's Path ~=91Kxf
private String sFileName; //Saved File's Name cih@:=Qy
private int nSplitter; //Count of Splited Downloading File :so2 {.t-
H6%QM}t
1$T;u~vg
public SiteInfoBean() '8\7(0$c
{//nSplitter的缺省值为5 Uyf<:8U\
//default value of nSplitter is 5 ]=\vl>W
this("","","",5); |C}n]{*|
} 3fPd|F.kF
V}gP'f07zy
!=%0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s+IU%y/9$a
{ Syv[[Ek
sSiteURL= sURL; </! `m8\
sFilePath = sPath; };;\&#
sFileName = sName; ^*JpdmVhu
this.nSplitter = nSpiltter; ,p2BB"^_i
9D@ $Y54
C><]o
} XJJdCv^
z\64Qpfm
{6H%4n
public String getSSiteURL() vC$Q4>m
{ ?^y%UIzf
return sSiteURL; [O~'\Q
} YDh6XD<Z
V)x(\ls]SX
|]=. ^
public void setSSiteURL(String value) LF o{,%B
{ 5A|4
sSiteURL = value; F>N3GPRl
} Arvxl(R\4
CbPCj.MH
o=/Cje
public String getSFilePath() ifA=qn0=}
{ u=j|']hp#&
return sFilePath; lIR0jgP@z
} -anLp8G*
e|Ip7`
)HZUCi/F]
public void setSFilePath(String value) #bRr|`
{ >)5=6{x
sFilePath = value; bpe8 `b(#
} #$\cRLPg
agQ5%t#
/cmnX'z
public String getSFileName() 'Na \9b(
{ 44s K2
return sFileName; XBJ9"G5
} >;E[XG^
c k~gB
5f54E|vD
public void setSFileName(String value) o;#{N~4[$
{ G5^gwG+
sFileName = value; fVR:m`'Iq_
} 7e,<$PH
U3ygFW%
6~g:"}
public int getNSplitter() tE)%*z@<Lt
{ H>AzxhX[n
return nSplitter; +B*8$^,V)
} ,v"/3Ff{,
nMU#g])y)
V/j]UK0$
public void setNSplitter(int nCount) Z&mV1dxR
{ eO,
nSplitter = nCount; V/5hEoDt
} b0a'Y"oef4
} (xU+Y1*g"%
Df_W>QC
ht^U VV2
/* 'e6W$?z
**Utility.java 0/.#V*KM
*/ .js4)$W^
package NetFox; 9X&Xs/B
;WIL?[;w
YYI
public class Utility { YQR*?/?a
6'C!Au
FV/xp}nz
public Utility() ,8(%J3J
{ VmQ7M4j*
GS{:7%=j
IidZ-Il
} </y V
Y51XpcXQ
//线程睡眠 F~d !Ub$>
public static void sleep(int nSecond) C!w@Naj
{ |D^Q}uT
try{ yZ:|wxVY
Thread.sleep(nSecond); SX}GKu
} whNRUOK:
catch(Exception e) ~4}m'#!
{ )<.S3
e.printStackTrace (); #)R;6"
} kt1f2cj
} nGW wXySq
KHr8\qLH
//日志 ^F?H)[0
public static void log(String sMsg) 17D167\X
{ r"fu{4aX
System.err.println(sMsg); ~s^&*KaA
} ?vRz}hiy
~Y)Au?d(a
Op3 IL/
public static void log(int sMsg) U7crbj;c)d
{ 54F([w
System.err.println(sMsg); $ O!f*lG
} Q,\lS
} 8KWTd
XQ(`8Jl&^
GWE`'V
/* `ss]\46>
**TestMethod.java 1rPeh{SZ
*/ A#1y>k
package NetFox; 4kXx(FE
56<LMY|d
l}Xmm^@)
public class TestMethod { UjKHGsDi4
$E7yJ|p{
)%j)*Ymz;
public TestMethod() qE,%$0g
{ ///xx/weblogic60b2_win.exe s?Q`#qD
try{ KktTR`W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g"Ii'JZ?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Xc|Z.6
SiteFileFetch fileFetch = new SiteFileFetch(bean); e9B,
fileFetch.start(); {iQ<`,)Y
} rkD4}jV
catch(Exception e){e.printStackTrace ();} 8%xtb6#7M
+^69>L2V
p`d:g BZ
} ^d=Z/d[
O_iX1@SW
ptDA))7M/
public static void main(String[] args) +$ -#V
{ e@,L~\
new TestMethod(); rLKDeB
} +?@qux!
} }bnkTC
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