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)); 8`XpcK-0
} = q9>~E{}
for(int i=0;i<nEndPos.length-1;i++) LL|$M;S
{ u:tLO3VfJ
nEndPos = nStartPos[i+1]; b<};"H0a
} w]X~I/6g
nEndPos[nEndPos.length-1] = nFileLength; D@*<p h=
} W4Rs9NA}
} ; S7 %
9Slx.9f
Bm2"} =
//启动子线程 = zW}vm }
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !:t}8
for(int i=0;i<nStartPos.length;i++) />c F
{ cdVh_"[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ql&5fyW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q4\EI=4P]
nStartPos,nEndPos,i); \&ra&3o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hE0 p>R8
fileSplitterFetch.start(); &dp<i[ec^
} Sx?IpcPSm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jR`q y<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tm~a&p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ++D-,>.
nEndPos = " + nFileLength); \L}aTCvG
// fileSplitterFetch[nPos.length-1].start(); &+;z`A'|8
RhIRCN9
zC#[
//等待子线程结束 dPgN*Bdv
//int count = 0; Jj4!O3\I
//是否结束while循环 S"0<`{Gv
boolean breakWhile = false; 3<sYxA\?w
pE<dK.v6
(b%&DyOt
while(!bStop) 8sjAr.iT.
{ pYIm43r H
write_nPos(); VSP6osX{
Utility.sleep(500); Wcd;B7OH
breakWhile = true; VCfa<hn
U|VFzpJ
2Sbo7e
for(int i=0;i<nStartPos.length;i++) B'"(qzE-kM
{ xU+c?OLi
if(!fileSplitterFetch.bDownOver) <|9s{z
{ l\<*9m<
breakWhile = false; >utm\!Gac
break; INqD(EG
} KR4X&d6
} BS*IrH H
if(breakWhile) [F{q.mZj
break; hbdq'2!Qr
89ivyv;]U
O& k+;r
//count++; ? hU0S
//if(count>4) `7$0H]*6
// siteStop(); ~x;1&\'k
} {#"[h1
w&<-pIa`
Xr'Y[E[
System.err.println("文件下载结束！"); hAq7v']m
} A+v6N>}*
catch(Exception e){e.printStackTrace ();} }tue`">h
} 60p*$Vqy
h^o>9s/|/H
'&?cW#J?
//获得文件长度 wh8h1I
public long getFileSize() A (z lX_
{ t@(S=i7}-
int nFileLength = -1; .`qw8e}y#'
try{ x&>zD0\ :\
URL url = new URL(siteInfoBean.getSSiteURL()); @9S3u#vP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sbn|D\p
httpConnection.setRequestProperty("User-Agent","NetFox"); VBV y3fnj
~5LlIpf36|
r5yp jT^
int responseCode=httpConnection.getResponseCode(); "`<tq#&C1
if(responseCode>=400) OSACH0h
{ j_L1KB*
processErrorCode(responseCode); C3 >X1nU
return -2; //-2 represent access is error ^1y (N>W
} 6iAHus-
_0^f
%%`Q5I
String sHeader; /J{ e_a
sk*AlSlM
j6x1JM
for(int i=1;;i++) n<RvL^T=
{ m/}(dT;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }>~';l
//Utility.log(in.readLine()); $OEhdz&Fi
sHeader=httpConnection.getHeaderFieldKey(i); Q'-g+aN
if(sHeader!=null) 17IT:T,'
{ oAaUXkQE
if(sHeader.equals("Content-Length")) e(nT2E
{ XIQfgrGZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BPRhGG|9j
break; *$+k-BV
} ,m ^q>
} .3Ex=aQcX
else ^yLiyRe\
break; IJX75hE0g
} 'Pk14`/
} `-Yo$b;:
catch(IOException e){e.printStackTrace ();} z*,P^K 0T
catch(Exception e){e.printStackTrace ();} rBNl%+ sB
?X{ul
)Pr*\<Cld
Utility.log(nFileLength); ,EhQTVJ
HCj/x<*F
J*V@huF
return nFileLength; : &! >.Y
} f0 iYP
@N^?I*|u
~+_|J"\
//保存下载信息（文件指针位置） $'m&RzZ
private void write_nPos() %K@s0uQ
{ lM0`yh
try{ 08*O|Ym,
output = new DataOutputStream(new FileOutputStream(tmpFile)); \~j6}4XS1.
output.writeInt(nStartPos.length); B?o ?LI
for(int i=0;i<nStartPos.length;i++) ~\4`tc
{ &U<t*"
// output.writeLong(nPos); #$/SM_X14C
output.writeLong(fileSplitterFetch.nStartPos); {|cuu"j26
output.writeLong(fileSplitterFetch.nEndPos); xOfZ9@VU
} u~ %xU~v
output.close(); x.gRTR`7(
} M? 7CBqZ
catch(IOException e){e.printStackTrace ();} 8&d s
catch(Exception e){e.printStackTrace ();} r7dvj#^
} <hG] f%
#L,>)XkjS
rID_^g_tP8
//读取保存的下载信息（文件指针位置） vpTYfE
private void read_nPos() 4(2iR0N
{ 'dTJE--@
try{ ur*a!U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |n9q4*dN
int nCount = input.readInt(); /m>%=_nz
nStartPos = new long[nCount]; !\e&7sV~Q
nEndPos = new long[nCount]; \gtI4zl*J
for(int i=0;i<nStartPos.length;i++) }vzZWe
{ -s]
nStartPos = input.readLong(); D)0pm?*5A
nEndPos = input.readLong(); IvJ;9d
} i,k.#Vx[m
input.close(); L H>oG$a
} =2sj$
catch(IOException e){e.printStackTrace ();} JI&ik_k3
catch(Exception e){e.printStackTrace ();} Ky6.6Y<.|
} Ndb_|
3WH"NC-O<
/Q|guJx
private void processErrorCode(int nErrorCode) 4q<LNvJA
{ .)eJL
System.err.println("Error Code : " + nErrorCode); .nGYx
} ry99R|/d1
pUTC~|j%:
V%kZ-P*
//停止文件下载 zxo0:dyw7
public void siteStop() A'jw;{8NpF
{ l8O12
bStop = true; ,2*^G;J1
for(int i=0;i<nStartPos.length;i++) L\O}q
fileSplitterFetch.splitterStop(); +i %,+3#6
u<}PcI.
ux8:
} HTpoYxn(
} ^;KL`
//负责部分文件的抓取 (C1@f!Z
**FileSplitterFetch.java >pS@;t'
*/ vbol70
package NetFox; ,[ogh
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O(P ,!
import java.io.*; 47(/K2
import java.net.*; hvc%6A\nm
naQ0TN,
*{/L7])gm
public class FileSplitterFetch extends Thread { /Ah|Po
Hh|a(Zq,
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String sURL; //File URL ^+v6?%m
long nStartPos; //File Snippet Start Position p-KMELB
long nEndPos; //File Snippet End Position AdCi*="m
int nThreadID; //Thread's ID p_K``JE
boolean bDownOver = false; //Downing is over ch^tq",1>
boolean bStop = false; //Stop identical ;,z[|"y
FileAccessI fileAccessI = null; //File Access interface xr }jw
#<^ngoOj
Ax'jNol
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8ec6J*b
{ ."8bW^:
this.sURL = sURL; z}L3//
this.nStartPos = nStart; \5k^zGF4o
this.nEndPos = nEnd; j|WuOZm\0
nThreadID = id; ISp'4H7R+N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G:n,u$2a<
} /^BaQeH?R
qQL]3qP
c(]NpH in
public void run() N[(ovr
{ D$ >gAv
while(nStartPos < nEndPos && !bStop) vCPiT2G
{ hH=H/L_Z
y093-
a0s6G3J+9
try{ `2 vv8cg^
URL url = new URL(sURL); U?%1:-#F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K >-)O=$s
httpConnection.setRequestProperty("User-Agent","NetFox"); dc ]+1 A
String sProperty = "bytes="+nStartPos+"-"; 0Q2P"1>KT/
httpConnection.setRequestProperty("RANGE",sProperty); 09_L^'`
Utility.log(sProperty); |'C{nTX
|.]:#)^X?
d"7l<y5
InputStream input = httpConnection.getInputStream(); 'CTvKW
//logResponseHead(httpConnection); 'dnTu@mUT
*1Q~/<W
dHE\+{K%-
byte[] b = new byte[1024]; FIB 9W@oao
int nRead; OZHQnvZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "zT#*>U
{ ~6:<OdQ
nStartPos += fileAccessI.write(b,0,nRead); q. %[!O
//if(nThreadID == 1) eyx;8v cM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B{:JD^V!
} h4j{44MT
QasUgZ
N*k`'T
Utility.log("Thread " + nThreadID + " is over!"); z[7j`J|Kk
bDownOver = true; ;:w?&4
//nPos = fileAccessI.write (b,0,nRead); (sngq{*%%z
} 8veYs`
catch(Exception e){e.printStackTrace ();} ?q&*|-%)_d
} XT n`$}nz
} v=(L>gg
UuNcBzB2d
:HDl-8]Lw
//打印回应的头信息 nm!5L[y!0
public void logResponseHead(HttpURLConnection con) t-xw=&!w
{ n1X.]|6'
for(int i=1;;i++) Dm,*G`Js
{ }d,iA FG
String header=con.getHeaderFieldKey(i); ^,Paih 2
if(header!=null) Y#'?3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lP4A?J+Q
Utility.log(header+" : "+con.getHeaderField(header)); jKOjw#N
else y~&R(x~w
break; uP'x{Pr)
} Ha U6`IP
} ur'a{BI2R
'>GZB
L_>j SP
public void splitterStop() XQ+KI:g2
{ IX!Q X
bStop = true; g$qNK`y
} ;P` z ?>J:
D6 2xC5
OygR5s +
} [V\0P,l
ls(lL\
~*Fbs! ;,
/* CS:"F) at
**FileAccess.java |@J:A!
*//文件访问(定位，写) RHV&m()Q
package NetFox; {b|:q>Be8
import java.io.*; -y8?"WB(b
z|VQp,ra
^Vl{IsY
public class FileAccessI implements Serializable{ ,ux?wa+
!nQ!J+ g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1-@[th
RandomAccessFile oSavedFile; NJEubC?
long nPos; ] ~;x$Z)
`@8QQB
+="?[:
public FileAccessI() throws IOException Iz'*^{Ssm
{ !N6/l5kn
this("",0); J|DID+M
} 3y}0J @
#d+bld\
"=7y6bM
public FileAccessI(String sName,long nPos) throws IOException xLfx/&2
{ n'<FH<x
oSavedFile = new RandomAccessFile(sName,"rw"); vT*z3
this.nPos = nPos; MuzlUW]
oSavedFile.seek(nPos); [m>kOv6>^
} eq0&8/=
.xRJ )9q
;\N{z6
public synchronized int write(byte[] b,int nStart,int nLen) G(LGa2;Zg
{ ?GdoB7(%
int n = -1; ?v]EXV3
try{ HPGMR4=ANS
oSavedFile.write(b,nStart,nLen); o%ZtE
n = nLen; 7J~usF>A
} MHs2UN
catch(IOException e) M.|@|If4?
{ ?Y:>Ouv*z'
e.printStackTrace (); 3},0b8};
} ;\P\0pI50
$wL zaZL|
>t-9yO1XQq
return n; {> T r22S
} }O_kbPNw
K{eq'F5M
7Eoa~
} +,`Cv_O
-L;sv0
D0'L
/* t5r,3x!E
**SiteInfoBean.java #0K122oY
*/ /%E X4 W
package NetFox; <:[P&Y
1#KE4(
2!Bjs?K<bv
public class SiteInfoBean { jQ &$5&o
SE%B&8ZD
#S?xRqkc
private String sSiteURL; //Site's URL ('H[[YODh
private String sFilePath; //Saved File's Path ~j%g?;#*
private String sFileName; //Saved File's Name 5)g6yV'
private int nSplitter; //Count of Splited Downloading File :VP*\K/:
B d#D*"gx
~>h_#sIBC
public SiteInfoBean() ,{"%-U#z
{//nSplitter的缺省值为5 )bJS*#
//default value of nSplitter is 5 vbH?[Zr?
this("","","",5); $a'n{EP
} ^gP pmb<x
,BGaJ|k
A*;I}F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ya[][!.G
{ V6opV&
sSiteURL= sURL; nVkPYeeT
sFilePath = sPath; J2rw4L
sFileName = sName; 4bV&U=
this.nSplitter = nSpiltter; tOn 6
(/x%zmY;/U
nE$8-*BZ_
} #\15,!*a=
13+f ^
1C,=1bY
public String getSSiteURL() TvV_Tz4e
{ B=E<</i
return sSiteURL; `zD]*i(
} M4MO)MYJ
8ZmU(m
N3J T[7
public void setSSiteURL(String value) uB;\nj5'D
{ z[zURj-*]
sSiteURL = value; 58S>B'
} {bQi z
xa7~{ E,
z?ck*9SZX
public String getSFilePath() >A'Q9Tia;
{ azEN_oUV
return sFilePath; "pQFIV,
} ]yc&ffe%
="~yD[S
x4b.^5"`:
public void setSFilePath(String value) FU;b8{Y
{ \6]Uj+
sFilePath = value; 9$]I3k
} BU3VXnqT[
kU*Fif
tw<mZd2H
public String getSFileName() <4l;I*:2&
{ [SnnOqWw
return sFileName; wrORyj
} 7/$r
F 7v 1rf]
oP[R?zN
public void setSFileName(String value) XsOz {?G
{ d7g3VF<j
sFileName = value; GJpQcse%
} uT")j,tz
}f/xMp-Y
FLWQY,
public int getNSplitter() w.AF7.X`1
{ 6p=OM=R
return nSplitter; ^p@R!228
} W~EDLLZ
uyE_7)2d
Kx8>
public void setNSplitter(int nCount) mA{G: d
{ "pa}']7#
nSplitter = nCount; A.f!SYV6
} J5i$D0K[
} C rA7lu'
w+^z{3>
WUEjWJA-MB
/* fga{b7
**Utility.java UKfC!YR2J8
*/ dV~d60jOF
package NetFox; 28u3B2\$
d9@Pze">e
qD#E, "%
public class Utility { #b^x!lR
h'QEwW
Sj,>O:p
public Utility() HU~,_m
{ ap 5D6y+
.}xF2'~E/
E%+aqA)f
} IJ#G/<ZJZ
_^Ds[VAgA
//线程睡眠 (]Zyk,[
public static void sleep(int nSecond) do-mkvk
{ oBBL7/L
try{ f@G3,u!]i
Thread.sleep(nSecond); <'Ppu
} :J 7p=sX
catch(Exception e) Zze(Ik
{ <Z0N)0|
e.printStackTrace (); $qvk9 B0E
} CrTGC%w{=
} 1u%e7
TB oN8cB}
//日志 ~|FKl%
public static void log(String sMsg) Uk2U:
{ *5Mg^}ZC5
System.err.println(sMsg); J)148/
} H#Aar
l^LYSZg'R8
|=\w b^l+
public static void log(int sMsg) oo+nqc`,O
{ ^GS,4[)H
System.err.println(sMsg); Boi?Bt
} %T_4n^beFQ
} @u4q\G\
Vm3e6Y,K
$<]G#&F
/* Za5bx,^
**TestMethod.java `1 tD&te0
*/ =7*k>]o
package NetFox; {H\(H_X
KRL9dD,&
2O*(F>>dT
public class TestMethod { 6wmMg i_m
!)nA4l=S#
c~bTK" u
public TestMethod() Ah|,`0dw
{ ///xx/weblogic60b2_win.exe {[i 37DN
try{ Wej'AR\NX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SccaX P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0-N"_1k|?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1=9M@r~ ^
fileFetch.start(); o1dECLQa
} ^hMJNy&R
catch(Exception e){e.printStackTrace ();} 52zD!(
RCgn\
byyzXRO;
} [q<Vm-
,g"[7Za
9"jhS0M
public static void main(String[] args) figCeJ!W4
{ \["'%8[:gR
new TestMethod(); ~.dmfA{
} | M|5Nc>W
} )-RI
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