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)); TCVl8)j
} E@)\Lc~
for(int i=0;i<nEndPos.length-1;i++) C*70;:b
{ KpiF0K
nEndPos = nStartPos[i+1]; 9h,u6e
} 5_o$<\I\
nEndPos[nEndPos.length-1] = nFileLength; ./-JbW
} }ynT2a#LU'
} E8}+k o
!b|'Vp^U
.w? .ib(
//启动子线程 s4= "kT]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0Fr1Ku!
for(int i=0;i<nStartPos.length;i++) b3qc_
{ VV_l$E$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B0UJq./`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZXb0Y2AVx
nStartPos,nEndPos,i); wdE?SDs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %'Xk)-+y
fileSplitterFetch.start(); &~DTZgY
} Z'v-F^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T6#"8qz<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'W. Vr4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v6a]1B
nEndPos = " + nFileLength); Jc*XXu)
// fileSplitterFetch[nPos.length-1].start(); kMxazx1
tJI,r_
w5C*L)l
//等待子线程结束 BNGe exs@
//int count = 0; WgR4Ix^L#
//是否结束while循环 *<V^2z$y_
boolean breakWhile = false; 3yS
TW&DFKK`
JN3cg
while(!bStop) ``Q2P%
{ 7YIK9edP
write_nPos(); D@YP7
Utility.sleep(500); p#8W#t$
breakWhile = true; {==pZpyyh
=(r* 5vd
$6f\uuTU2"
for(int i=0;i<nStartPos.length;i++) B)SLG]72f
{ vFmJ;J
if(!fileSplitterFetch.bDownOver) vxlOh.a|/L
{ wzcai 0y*
breakWhile = false; USML~]G z
break; v[k5.\No
} \&xl{64
} JQKdW
if(breakWhile) V2&^!#=s
break; 25{ uz
**_&i!dtL
")#<y@Rv
//count++; ak:v3cQR
//if(count>4) qztV,R T
// siteStop(); > 6CV4 L
} !3&kQpF
8|1^|B(l
Eh8Pwt7C@
System.err.println("文件下载结束！"); 2h~-
} f?fKhu2
catch(Exception e){e.printStackTrace ();} N"5fmY<
} +54aO
VkmRh,T
D@Da0
//获得文件长度 8pZ<9t'
public long getFileSize() t@zdmy
{ KlxN~/gyik
int nFileLength = -1; "`tXA
try{ eBW=^B"y+
URL url = new URL(siteInfoBean.getSSiteURL()); Jcf"#u-Q/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P8yIegPY
httpConnection.setRequestProperty("User-Agent","NetFox"); nn~YK
C"<s/h
TvhJVVQ+?
int responseCode=httpConnection.getResponseCode(); my\&hCE
if(responseCode>=400) Iq5pAHm>M6
{ b}z`BRCc
processErrorCode(responseCode); .#6MQJ]OH
return -2; //-2 represent access is error RNJFSD.
} NC23Z0y
'%iPVHK7
PBqy F
String sHeader; +",S2Qmo
$K}. +`vVO
('k<XOi
for(int i=1;;i++) @M;(K<%h
{ ?s%v0cF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $< %B#axL
//Utility.log(in.readLine()); |WqOk~)[Z3
sHeader=httpConnection.getHeaderFieldKey(i); 7v~j=Z>
if(sHeader!=null) 'VnwG
{ c=p=-j=.J
if(sHeader.equals("Content-Length")) T.&7sbE_
{ `x8Bn"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8QgA@y"
break; u</8w&!
} I+?hG6NM
} t1]6(@mj5
else qk{'!Ii
break; <lwuTow
} %IZ)3x3l
} JNU/`JN9f
catch(IOException e){e.printStackTrace ();} }<m{~32M
catch(Exception e){e.printStackTrace ();} ;2`sN
}7/e8 O2
E)p9eU[#
Utility.log(nFileLength); sa-9$},z4
6F0(aGs
v"6 \=@
return nFileLength; 59 2;W-y
} V^fV7hw<
:-+4:S
NlPS#
//保存下载信息（文件指针位置） 2Oc$+St~8
private void write_nPos() ? 5|/ C
{ 2ypIq
try{ ISqfU]>[
output = new DataOutputStream(new FileOutputStream(tmpFile)); $ @1u+w
output.writeInt(nStartPos.length); ZW4aY}~)$
for(int i=0;i<nStartPos.length;i++) mf$j03tu
{ YcM;S
// output.writeLong(nPos); t 0O4GcAN
output.writeLong(fileSplitterFetch.nStartPos); f?UzD#50D
output.writeLong(fileSplitterFetch.nEndPos); L10IF
} %_)zWlN
output.close(); [s6C ZcL
} 7!4V>O8@
catch(IOException e){e.printStackTrace ();} >.%4~\U
catch(Exception e){e.printStackTrace ();} 1=GI&f2I
} kA?_%fi1
aq>?vti1D
M@7Xp)S"
//读取保存的下载信息（文件指针位置） Ej(2w Q
private void read_nPos() h[Tk;h
{ ] f7#N
try{ "~+.Af
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )C]x?R([m
int nCount = input.readInt(); V0i9DK|!
nStartPos = new long[nCount]; G?)vWM`j
nEndPos = new long[nCount]; .Ao0;:;(2-
for(int i=0;i<nStartPos.length;i++) MK$Jj"
{ q? z>
nStartPos = input.readLong(); |ng%PQq)
nEndPos = input.readLong(); s@@1 *VQ
} Ob@Hng%v
input.close(); BWK IbG
} f6ZZ}lwaV
catch(IOException e){e.printStackTrace ();} I48VNX
catch(Exception e){e.printStackTrace ();} ,@CfVQz
} LJuW${Y
8C&x MA^
Gp2!xKgm
private void processErrorCode(int nErrorCode) lgD]{\O$ip
{ &d^=siL
System.err.println("Error Code : " + nErrorCode); %$X\"
} zQfkMa.
qd2xb8r
i57( $1.
//停止文件下载 y?:dE.5p|
public void siteStop() YMzBAf
{ /^<en(0=P
bStop = true; !D:k!
for(int i=0;i<nStartPos.length;i++) ,)#.a%EKA
fileSplitterFetch.splitterStop(); zY APf &5
/6tcSg)
EZj1jpL
} vDDljQXw4
} C3"&sdLb$
//负责部分文件的抓取 $G";2(-k
**FileSplitterFetch.java gA:TL{X0
*/ 0D3OE.$0
package NetFox; tbur$00
[X"k> Sq
VTw/_Hf2p
import java.io.*; ~ =.CTm]vf
import java.net.*; $$gtZ{ukQ
0s%6n5>
SGf9U^ds
public class FileSplitterFetch extends Thread { P;U@y"s
>4)g4~'n!
YKx 1NC
String sURL; //File URL Jt=>-Spj
long nStartPos; //File Snippet Start Position g9V.13k
long nEndPos; //File Snippet End Position 5' \)`
int nThreadID; //Thread's ID -u6#-}S
boolean bDownOver = false; //Downing is over lX;mhJj!
boolean bStop = false; //Stop identical MUwVG>b8J~
FileAccessI fileAccessI = null; //File Access interface /$`;r2LG
h}6_ybmZ
tgN92Q.i6T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #5{sglC"|F
{ j%xBo:
this.sURL = sURL; Bw-s6MS
this.nStartPos = nStart; Vyt E
this.nEndPos = nEnd; *{[d%B<lp
nThreadID = id; [x_s/"Md;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rm|7 [mK
} %V_eJC""?
$9H[3OZPVv
jT^!J+?6K+
public void run() Bl4 dhBZoO
{ fN[n>%)VO<
while(nStartPos < nEndPos && !bStop) pGkef0p@
{ 9ECS,r*B
0vckoE
_S5gcPcF"
try{ !;WbOnLP
URL url = new URL(sURL); -1mvhR~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d}% (jJ(I
httpConnection.setRequestProperty("User-Agent","NetFox"); `o-*Tr
String sProperty = "bytes="+nStartPos+"-"; lU$X4JBzS
httpConnection.setRequestProperty("RANGE",sProperty); z93nYY$`Y
Utility.log(sProperty); ;&mxqY8`'
6ZgNHARS
ZNy9_a:dX
InputStream input = httpConnection.getInputStream(); I9/KM4&
//logResponseHead(httpConnection); %UG/ak%z
^pw7o6}
=uc^433.
byte[] b = new byte[1024]; $rB!Ex{@ac
int nRead; ?`i|"y#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b%<jUY
{ P#bm uCOS
nStartPos += fileAccessI.write(b,0,nRead); *`.LA@bHU
//if(nThreadID == 1) yA}nPXrd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BhkAQEsWTQ
} Iaa|qJ4
Wa, 7P2r
p">WK<N
Utility.log("Thread " + nThreadID + " is over!"); {X]9^=O"
bDownOver = true; .EzSSU7n)
//nPos = fileAccessI.write (b,0,nRead); 3_U\VGm
} enPYj.*/0
catch(Exception e){e.printStackTrace ();} Hdna{@~
} sH@ &*
} U,HS;wo;t
6vWii)O.D
s((b"{fFb
//打印回应的头信息 ">,K1:(D
public void logResponseHead(HttpURLConnection con) Ou!)1UFI
{ eoL0^cZj
for(int i=1;;i++) B[7A
{ FvA|1c
String header=con.getHeaderFieldKey(i); @7X\tV.Z
if(header!=null) QX+Y(P`vMK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'A1E^rl]=
Utility.log(header+" : "+con.getHeaderField(header)); *vD/(&pQ1:
else E6Q91Wz9f
break; QRiF!D)Nk
} 0STk)>3$-
} SZE`J:w
4K'|DO|dH
ZmP1C`>
public void splitterStop() o{g@Nk'f
{ ~D_rZ&
bStop = true; :SdIU36
} C#T)@UxBZ
.W-=x,`hY4
.Nk6
} *V<)p%l.
3l+|&q[v
0@w&J9yG
/* -BjEL;
**FileAccess.java /rOnm=P+Q
*//文件访问(定位，写) Y`q!V=
package NetFox; w&9F>`VET
import java.io.*; \CDAFu#
7s!AHyZ
%'kX"}N/
public class FileAccessI implements Serializable{ JkJhfFV
> `0| X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yq!CWXZ2
RandomAccessFile oSavedFile; ~6MMErSj
long nPos; (w}r7`n
qjzZ}
69-$Wn43<
public FileAccessI() throws IOException y^, "gD
{ '&/(oJ;O~
this("",0); % hNn%Oy:E
} @_(nd57oSs
G1A$PR
-z&9DWH
public FileAccessI(String sName,long nPos) throws IOException VBhE{4J
{ ?3n=m%W,J*
oSavedFile = new RandomAccessFile(sName,"rw"); qPp]K?.
this.nPos = nPos; 2,+@#q
oSavedFile.seek(nPos); rdFs?hO
} pDP33`OFh
<%he o
rT o%=0P
public synchronized int write(byte[] b,int nStart,int nLen) 1XQ87~
{ )!BB/'DRQ
int n = -1; KqFmFcf|
try{ s!bHS_\e|
oSavedFile.write(b,nStart,nLen); +V6j`
n = nLen; rknzo]N,
} MG;4M>H
catch(IOException e) IM$'J
{ LxIuxt=X|p
e.printStackTrace (); `Nkx7Z~w:
} 7eTA`@v5A
;.L!%$0i#
`Uu^I
return n; G &m>Ov$#&
} [;)~nPjI
:U7;M}0
n})
} $&bU2]
DrW/KU,{+(
LPsh?Ca?N
/* %L.lkRs
**SiteInfoBean.java _P>1`IR
*/ l)|z2H
package NetFox; !d/`[9jY
<Wp`[S]r
9Y;}JVS
public class SiteInfoBean { <?{ SU
\XZU'JIO
*{HGLl|=
private String sSiteURL; //Site's URL *sIi$1vHu
private String sFilePath; //Saved File's Path h\Z3yAYd
private String sFileName; //Saved File's Name hLu&lY
private int nSplitter; //Count of Splited Downloading File o,iS&U"TC
Z?5,cI[6#
u!sSgx=
public SiteInfoBean() M|5^':Y
{//nSplitter的缺省值为5 ^w.k^U=B
//default value of nSplitter is 5 VG? yL2y
this("","","",5); A)=X?x
} @oUf}rMiDa
Lx9hq7<
FA5k45wL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T9aTEsA[U
{ '&rw=.cU
sSiteURL= sURL; B(HNB\3u
sFilePath = sPath; ch%Q'DR_I)
sFileName = sName; 0:~gW#lD
this.nSplitter = nSpiltter; J+-,^8)
K+(m'3`
c`Lpqs`
} <h)deB+}
rCV$N&rK
LX&=uv%-^
public String getSSiteURL() !H2C9l:rd
{ '5&B~ 1&
return sSiteURL; Ut0qrkqF
} 37GHt9l
&QiAM`MbC=
/ nC$?w
public void setSSiteURL(String value) :/I={)5
{ pP=_@3 D
sSiteURL = value; M)bC%(xJ
} vq@#Be?@
%t,1_c0w
%a%+!wX0x
public String getSFilePath() O% j,:t'"
{ So3,Z'z=
return sFilePath; D| 3AjzW
} ?#');`
oZ|{J
Xmw2$MCB
public void setSFilePath(String value) J~PTVR
{ 0ll,V
sFilePath = value; NpjsZcA
} Br?++\
~cWLu5
Pj^k pjV
public String getSFileName() ~8S4Kj)%
{ U^WQWa
return sFileName; 'Y6(4|w (
} hNgcE,67q
9 u6 g
Y D1g]p
public void setSFileName(String value) TU^tW
{ QZeb+r
sFileName = value; Tg}H < T
} .-gm"lB
LQuYCfj|
B%?|br
public int getNSplitter() (rCPr,@0
{ pD)/-Dgdm
return nSplitter; W"DxIy
} s`dkEaS
w^vK7Z 1$
0o\=0bH&s
public void setNSplitter(int nCount) J0{WqA.P
{ G/^5P5y%@
nSplitter = nCount; 2gNBPd)I
} tF)k6*+
} ^!{ oAzy9
t2U]CI%
e=NQY8?
/* Z2Y583D
**Utility.java wLg:YM"
*/ RaJ}>e
package NetFox; FkkZyCqZ`
#6#BSZ E
#gr+%=S'6C
public class Utility { m/"=5*pA
&dHm!b
F'T= Alf
public Utility() A1&>L9nUx
{ 7Ohu$5\
L<nkI
A+Pm "|
} m$G?e9{
2v; 7ohK
//线程睡眠 D=Yag!1
public static void sleep(int nSecond) Y_TL4
{ "#"Fp&Z7
try{ e&VR>VJEA
Thread.sleep(nSecond); 0zkT8'v
} c&iK+qvh{
catch(Exception e) 4FP~+
{ |'>E};D
e.printStackTrace (); _S7M5{U_
} clU3#8P!=
} 9jJ/ RXp
JCMEhI6d*
//日志 >@92K]J
public static void log(String sMsg) |<o>$;mZ
{ RHA>fXp
System.err.println(sMsg); WSX@0A.&)
} z]R!l%`
UEdl"FwM4
^_"q`71Dk
public static void log(int sMsg) K^1O =1gY
{ cbHn\m)J,
System.err.println(sMsg); "5z6~dq
} lr= !:D=K
} F7PZV+\
^zs4tCW%
e"8m+]
/* =xQfgj
**TestMethod.java .TrQ +k>
*/ "u>sS
package NetFox; ucm.~1G(
?;=Y1O7N(
9Z_OLai
public class TestMethod { 'V1 -iJj9
UHDI9>G~,
u:>3j,Cs
public TestMethod() C%7,#}[U/
{ ///xx/weblogic60b2_win.exe 9/qS*Zdh)
try{ uL{~(?U$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?@ye*%w_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1ROgUJ;
SiteFileFetch fileFetch = new SiteFileFetch(bean); .j$bCKXGx
fileFetch.start(); ("@V{<7(t
} &_x/Dzu!z
catch(Exception e){e.printStackTrace ();} _nCs$U
2/o/UfYjgF
W;9X*I8f8
} 'f<_SKd
,f""|X5
[LEh
public static void main(String[] args) Hbj:CViYq
{ #YMp,i
new TestMethod(); <$Kv^Y*
} \EfwS% P
} blkJm9]v
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