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)); 3BK 8{/
} >P(.yQ8&kL
for(int i=0;i<nEndPos.length-1;i++) /Cwwz
{ jHT^I as
nEndPos = nStartPos[i+1]; U7U&^s6`
} v" #8^q
nEndPos[nEndPos.length-1] = nFileLength; ]Rf$&7`g{
} F&p42!"
} 3`D*AFQc
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<}&J|()
//启动子线程 !b0A%1W;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w$s6NBF7
for(int i=0;i<nStartPos.length;i++) gZ>&cju
{ 9`qw,X&AK_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WllQM,h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p:tp|/
nStartPos,nEndPos,i); 9:%')M&Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i\ 7JQZ
fileSplitterFetch.start(); cfBlHeYE
} u-.5rH l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q>X1 :Zn3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pdN8hJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zO9WqP_`iR
nEndPos = " + nFileLength); dw}ge,bBic
// fileSplitterFetch[nPos.length-1].start(); Tl"r#
oEZhKVyc.y
J7WNgl% u
//等待子线程结束 KX\=wFbP)
//int count = 0; /!5cf;kl*l
//是否结束while循环 m_ wvi
boolean breakWhile = false; r;(^]Soz
OJydt;a
StNA(+rT
while(!bStop) &!:mL],
{ 0%rE*h9+
write_nPos(); wmbG$T%k
Utility.sleep(500); Mf5*Wjz.Mc
breakWhile = true; 4Af7x6a;
s 64@<oU<"
&`!H1E^
for(int i=0;i<nStartPos.length;i++) \ D>!&
{ x^`P[>
if(!fileSplitterFetch.bDownOver) LCIe1P2
{ USgO`l\}4
breakWhile = false; UY *Z`$
break; #Wl9[W/4
} 'g<FL`iP
} AKLFUk
if(breakWhile) Y!c7P,cZ+3
break; b,ZBol|X
FFVh~em{
lUnC+w#[
//count++; LChwHkRHJI
//if(count>4) ?:vB_@
// siteStop(); r<dvo%I#|
} ^5!"[RB\
W^,p2
4e[ 0.2?
System.err.println("文件下载结束！"); _w <6o<@
} w2!5TKZ`
catch(Exception e){e.printStackTrace ();} =td(}3|D Y
} BG-nf1K(
Y)S f;
QUXr#!rPY|
//获得文件长度 ?ODBW/{[G
public long getFileSize() M@. 2b.
{ ygV-Fv>PQ
int nFileLength = -1; S[/D._5QD%
try{ DoeE=X*`k
URL url = new URL(siteInfoBean.getSSiteURL()); <c(%xh46
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1X&scVw
httpConnection.setRequestProperty("User-Agent","NetFox"); maQDD*
rc{F17~vX
]K5j(1EN
int responseCode=httpConnection.getResponseCode(); 68qCY
if(responseCode>=400) V22Br#+
{ f0{tBD!%
processErrorCode(responseCode); bC&xN@4
return -2; //-2 represent access is error d$MewDWUN
} u]3VK
i#U_g:~wC
d\ 7OtM
String sHeader; 8f&#WIZ
uF*tlaV6
%yVP@M
for(int i=1;;i++) ]>(pQD
{ kI*f}3)Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SV1;[
//Utility.log(in.readLine()); kkT=g^D9j
sHeader=httpConnection.getHeaderFieldKey(i); t/x]vCP,2D
if(sHeader!=null) :WSszak
{ 5.Nc6$ N
if(sHeader.equals("Content-Length")) #@uF?8u
{ %SMP)4Y/R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?+{qmqN
break; 2:^
} f5CnJhE|)
} =~$)Ieu
else GtqA@&5&
break; c#[d7t8ONe
} a&n}pnEn)
} 9aKCO4
catch(IOException e){e.printStackTrace ();} _ba.oIc
catch(Exception e){e.printStackTrace ();} x@VZJrQQ
N2EX`@_2
PrEfJ?
Utility.log(nFileLength); 2\xEMec
tjDCfJx*
KJ6:ZTbW
return nFileLength; &K,rNH'R
} 6~8X/ -02
A0uA\E4q
G9c2kX.Bf
//保存下载信息（文件指针位置） +,0 :L :a
private void write_nPos() -hO[^^i9
{ ='.G,aJ9
try{ -~=:tn)0
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jy#21
output.writeInt(nStartPos.length); NK(; -~{P
for(int i=0;i<nStartPos.length;i++) YjeHNPf
{ PKNpR
// output.writeLong(nPos); Si[xyG6=
output.writeLong(fileSplitterFetch.nStartPos); uI&<H T?
output.writeLong(fileSplitterFetch.nEndPos); IlP@a[:_
} 9Or
output.close(); l:"zYcp%
} (qy82F-|2
catch(IOException e){e.printStackTrace ();} x4S0C[k
catch(Exception e){e.printStackTrace ();} TSYe~)I
} a)M#O\i`
rt!Uix&
vqBT^Q_q;
//读取保存的下载信息（文件指针位置） G2_l}q~
private void read_nPos() kF"G {5
{ O(44Dy@2
try{ JclG*/Wjg4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %-, -:e
int nCount = input.readInt(); ~]lVixr9
nStartPos = new long[nCount]; 8` f=Eh
nEndPos = new long[nCount]; ew6\Z$1c~
for(int i=0;i<nStartPos.length;i++) .Vb\f
{ 2/G`ej!*
nStartPos = input.readLong(); \}})U#
nEndPos = input.readLong(); vWpkU<&3|
} A/U,|
input.close(); ?Kf?Z`9 *Y
} "0A !fRI~
catch(IOException e){e.printStackTrace ();} ;1woTAuD
catch(Exception e){e.printStackTrace ();} wWUt44:0O
} P}C;%KzA
y@Ga9bI7
YumHECej
private void processErrorCode(int nErrorCode) tcS7 @^'
{ x[H9<&)D
System.err.println("Error Code : " + nErrorCode); r081.<
} w 7 j hS
>Sh"/3%q
6):^m{RH^
//停止文件下载 {nlqQ.jO
public void siteStop() OBmmOswg~
{ +zLh<q0
bStop = true; h4dT N}
for(int i=0;i<nStartPos.length;i++) k'$UA$2d
fileSplitterFetch.splitterStop(); `}9jvR5
h\qM5Qx+Q
T*sB Wn'am
} )\r;|DN
} Z3]ut#`
//负责部分文件的抓取 ~Uw<E:?v
**FileSplitterFetch.java ~$3X>?Q
*/ `(7HFq<N
package NetFox; cu V}<3&
8HymkL&F
aI0}E O
import java.io.*; ^(8(z@y
import java.net.*; ~%o?J"y
kdHP v=/U
#4<Rs|K
public class FileSplitterFetch extends Thread { m"Y|xvIA
6~j.S "
QX j4cg
String sURL; //File URL &7\q1X&Rr
long nStartPos; //File Snippet Start Position 3d|n\!1r
long nEndPos; //File Snippet End Position :. ja~Q
int nThreadID; //Thread's ID w;p!~o &
boolean bDownOver = false; //Downing is over 0au\X$)Q
boolean bStop = false; //Stop identical zg=F;^oZ<
FileAccessI fileAccessI = null; //File Access interface 4uG:*0{Yx
7VQk$im399
WhHnF*I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aD,(mw-7r
{ h5?yrti
this.sURL = sURL; +u:Q+PkM
this.nStartPos = nStart; ,TAzJ
this.nEndPos = nEnd; |P"p/iY
nThreadID = id; z"C+r'39d=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ` E2@GX+,
} i; 3^vhbQ
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public void run() qs]7S^yw
{ pkR+H|
while(nStartPos < nEndPos && !bStop) C r~!N|(
{ >=_Z\ wA
P|OjtI
bQ"w%!
try{ MQv2C@K9F
URL url = new URL(sURL); Ux Yb[Nbc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KF[P /cFI
httpConnection.setRequestProperty("User-Agent","NetFox"); MH>CCT
String sProperty = "bytes="+nStartPos+"-"; /J"U`/ {4
httpConnection.setRequestProperty("RANGE",sProperty); [z1[4
Utility.log(sProperty); `E),G;I
.D`""up|{
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InputStream input = httpConnection.getInputStream(); 0{PRv./`
//logResponseHead(httpConnection); p/a)vN+*x'
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byte[] b = new byte[1024]; |oSx*Gh
int nRead; 3UBg"1IC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |lijnfp
{ : _>/Yd7-&
nStartPos += fileAccessI.write(b,0,nRead); kR0d]"dr
//if(nThreadID == 1) *$ihNX]YG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?{"_9g9
} il \q{Y o
*k(>Qsb "
rN'')n/F
Utility.log("Thread " + nThreadID + " is over!"); _O-ZII~
bDownOver = true; Er6'Ig|U
//nPos = fileAccessI.write (b,0,nRead); hYS*J908
} ?vgHu
catch(Exception e){e.printStackTrace ();} :Z@!*F
} 2<*DL6
} =jX'FNv#
;c'9Xyl-
4$+9Wv
//打印回应的头信息 FBYAd@="2
public void logResponseHead(HttpURLConnection con) 75t\= 6#
{ M8 E8r
for(int i=1;;i++) z#8d\X/
{ ;Q;u^T`
String header=con.getHeaderFieldKey(i); Q-X<zn
if(header!=null) S1<mO-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c8cV{}7Kb
Utility.log(header+" : "+con.getHeaderField(header)); +@Oo)#V|.
else fXPD^}?Ux4
break; e7<//~W7W
} =U6%Wdth
} S0_#h)
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m8q3Pp
public void splitterStop() 9}{i8 <$=
{ A d0dg2Gw
bStop = true; Cc?BJ
} )19As8rL/o
B*+3A!{s
idLysxN
} ^ $M@yWX6
\(PC#H%
Xj/U~
/* ^<8 c`k )e
**FileAccess.java DlkHE8r\
*//文件访问(定位，写) (GVH#}uB
package NetFox; =|lKB;
import java.io.*; NzmVQ-4
Fg3VD(D^U
"JLKO${ Y
public class FileAccessI implements Serializable{ .!ThqYo
{ jnQoxN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *^XfEO
RandomAccessFile oSavedFile; "x.|'
long nPos; LLn,pI2fL{
KLI(Rve24
'2u(fLq3h
public FileAccessI() throws IOException xS) njuq4
{ }t tiL
this("",0); [TAW68f'
} ,O@xv
AnV\{A^
h 7feZ_
public FileAccessI(String sName,long nPos) throws IOException ]&za^%q0&
{ a D*
oSavedFile = new RandomAccessFile(sName,"rw"); nR7 usL
this.nPos = nPos; /P~@__XN
oSavedFile.seek(nPos); sN^3bfi!i
} &+?JY|u
@(Mg>.P
stDrF1{
public synchronized int write(byte[] b,int nStart,int nLen) fUh7PF%
{ D"WqJcDt
int n = -1; ,?"cKdiZ
try{ pKf]&?FX
oSavedFile.write(b,nStart,nLen); 1]HEwTT/1_
n = nLen; FE+Y#
} 6&pI{
catch(IOException e) V6.xp{[
{ 3:Aw.-,i\
e.printStackTrace (); IL?mt2IQ>
} \#P>k;D
D(}w$hi8
D];%Ey
return n; ,6,sz]3-
} 3/P#2&jt
,EyZ2`|
#rL%K3'
} KdT1Nb=
MP|J 0=H5
(9_~R^='y
/* cqzd9L6=
**SiteInfoBean.java ~f&lQN'1
*/ OI3UC=G
package NetFox; L&wJ-}'l
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d\Xi1&&
public class SiteInfoBean { rlEp&"+|M
yUb$EMo\
'j84-U{&)
private String sSiteURL; //Site's URL ,wJ#0?
private String sFilePath; //Saved File's Path |1GR:b24
private String sFileName; //Saved File's Name v:*t5M >
private int nSplitter; //Count of Splited Downloading File $vNz^!zgV
2ZMYA=[!
W=v4dy]B
public SiteInfoBean() f\sxx!kt
{//nSplitter的缺省值为5 :3k&[W*
//default value of nSplitter is 5 o8+ZgXct
this("","","",5); t?NB#/#%x
} 0GR\iw$[J
ze!S4&B
HC0q_%j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aa8xo5tIp
{ gxEa?QH
sSiteURL= sURL; s;'XX}Y
sFilePath = sPath; CmaV>
sFileName = sName; ]:CU.M1
this.nSplitter = nSpiltter; 8(R%?>8
>}#h
&61;v@
} 7Y$#* 7
W2L:
w%=GdA=
public String getSSiteURL() TrxZS_
{ j4wcxZYY~
return sSiteURL; ,?Pn-aC+
} #J.v[bOWQ
h^F^|WT$
!8q+W`{
public void setSSiteURL(String value) z?$F2+f&
{ {HKd="%VG
sSiteURL = value; G}aw{Vbg_
} # Ny
l4+!H\2
NET?Ep
public String getSFilePath() JcsJfTI
{ (lwrk(
return sFilePath; <rUH\z5cP
} QUL^]6$
0HUSN_3F
%c%0pGn8-
public void setSFilePath(String value) =[8EQdR
{ BZy&;P
sFilePath = value; VeO$n*O
} iOpMU
jEj#|w
)X{x\ /N
public String getSFileName() %u\Oj \8U
{ *"V5j#F_
return sFileName; :[:5^R
} 6e,|HV
D>9~JHB
tx}}Kd
public void setSFileName(String value) y:Xs/RS
{ L/1zG/@
sFileName = value; l2uh"!
} wjk-$p
sS5 ]d8
Rk2V[R.`S
public int getNSplitter() |FZ)5
{ DA)+)PhY7K
return nSplitter; Q3MG+@)S
} D"o}XTH
1PWs">*(
,]?Xf>
public void setNSplitter(int nCount) NNZ%jJy?=,
{ ":E^&yQ
nSplitter = nCount; 7Iu^l4=2
} %VG;vW\V
} d (Ufj|;
Y1a[HF^-
,bT|:T@ny
/* M,]C(f>
**Utility.java 3R(GO.n=]
*/ B6)d2O9C
package NetFox; !mNXPqnN
VU+`yQp
IXb]\ )
public class Utility { } ).rD
,at"Q$)T
x)eYqH~i
public Utility() K_/8MLJQ
{ $qkVu
4Q2=\-KFj
}7iWmXlI
} PI{;3X}9$,
;J|sH>i
//线程睡眠 *,$cW,LN
public static void sleep(int nSecond) 9(?9yFbj5
{ Cz=HxU80J
try{ SN!TE,=I
Thread.sleep(nSecond); s*`_Ka57]~
} >ZMB}pt`
catch(Exception e) A4RA5N/}
{ XWH{+c"
e.printStackTrace (); Il(p!l<Xz#
} 5W/!o&x~7
} _`yd"0Ux
pME17 af
//日志 ZH8O%>!
public static void log(String sMsg) r[xj,eIb
{ \_?A8F
System.err.println(sMsg); VwfeaDJw
} ^):m^w.
$hexJzX
~B!O X
public static void log(int sMsg) 9kmEg$WM
{ 0zrgK;9
System.err.println(sMsg); DG& ({vy
} (XtN3FTY
} eQh@.U*S)
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oRl~x^[%[-
/* Xv[5)4N
**TestMethod.java 6&8([J
*/ 8bQ\7jb
package NetFox; Vfkm{*t)
O <;Au|>*
l,cnMr^.W
public class TestMethod { ks92-%;:
up+W[#+
v+a$Xh3Y~
public TestMethod() u{#}Lo>B #
{ ///xx/weblogic60b2_win.exe e>yPFXSk
try{ Y~ j.Kt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (Fc\*Vn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2$=U#!OtU
SiteFileFetch fileFetch = new SiteFileFetch(bean); \Fd6Q_
fileFetch.start(); NfG<!
} B/"TaXVU
catch(Exception e){e.printStackTrace ();} ,(d\!T/]'
: utY4
?y1']GAo
} AY]dwKw
}DH3_M!
}^|g|xl!
public static void main(String[] args) uTsxSkHb/
{ {Ju
new TestMethod(); Z(Styn/x
} a?Q\nu1
} W+HiH`Qb]
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