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)); `toSU>:
} p_qH7W
for(int i=0;i<nEndPos.length-1;i++) H~ (I
{ l_DPlY
nEndPos = nStartPos[i+1]; fY>\VY$>
} ,u$$w
nEndPos[nEndPos.length-1] = nFileLength; A1i-QG/6
} |ek*wo
} 7%JXVP}A
b\}`L"
])e6\)
//启动子线程 #*w$JH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t#kmtJC
for(int i=0;i<nStartPos.length;i++) =MMWcK&
{ yp8 .\.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K":-zS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7 0KZXgBy_
nStartPos,nEndPos,i); m"u 9AOHk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N#|c2n+
fileSplitterFetch.start(); (RGl, x:
} N:=D@x~]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Il!iqDHz3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w:pc5N>we0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W&GDE
nEndPos = " + nFileLength); RL($h4d9
// fileSplitterFetch[nPos.length-1].start(); 0\u_\%[
i;yz%Ug
|`#[jHd
//等待子线程结束 n_iq85
//int count = 0; )-[X^l j
//是否结束while循环 7v1}8Uk
boolean breakWhile = false; tw^V?4[Miu
!SVW}Q=5#
Z3 &8(vw
while(!bStop) ]kc]YO7i%R
{ T<P4+#JK
write_nPos(); \\)3:1X
Utility.sleep(500); 'M YqCfIK
breakWhile = true; aNfgSo05@n
<PXA`]x~
S tn[M|
for(int i=0;i<nStartPos.length;i++) %$Mvq&ZZ
{ >pz/wTOi
if(!fileSplitterFetch.bDownOver) L[rJ7:
{ :Ruj;j
breakWhile = false; 350y6pVh
break; {{:MJ\_"h_
} Dr<%Lr
} |(Io(e
if(breakWhile) ePB=aCZ
break; 5Gg`+o
'Zk&AD ~
ykM(` 1`m
//count++; 7-bU9{5
//if(count>4) R>#T{<<L
// siteStop(); }Li24JK
} BwrMRMq"
#2|sS|0<
<"aPoGda
System.err.println("文件下载结束！"); m &c8@-T
} SbrBlP:G
catch(Exception e){e.printStackTrace ();} >e"1a/2%>&
} 4LKOBiEM
7RTp+FC]
N!^U{;X7/
//获得文件长度 :8MpSvCV
public long getFileSize() 7teg*M{
{ M {_`X
int nFileLength = -1; cD]{ Nn
try{ ppfBfMX
URL url = new URL(siteInfoBean.getSSiteURL()); |Ax~zk;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X|@|ZRN
httpConnection.setRequestProperty("User-Agent","NetFox"); 8x[q[
jcv3ES^
$v$~.
int responseCode=httpConnection.getResponseCode(); jja9:$#
if(responseCode>=400) mp%i(Y"vp
{ \"5%w *vl
processErrorCode(responseCode); X{<j%PdC
return -2; //-2 represent access is error #2{ };)
} 5(tOQ%AQ
!~"q$T>@
[uW{Ap~2
String sHeader; YjoN:z`b
k g0Z(T:&8
mS0*%[S {
for(int i=1;;i++) %)u5A!"
{ >/eQjp?:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qbFzA i
//Utility.log(in.readLine()); ]7fqVOiOu
sHeader=httpConnection.getHeaderFieldKey(i); %v4/.4sR,;
if(sHeader!=null) V<?t(_Y
{ 6ZR'1_i6i=
if(sHeader.equals("Content-Length")) x$?{)EY
{ {{SeD:hx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v.c2(w/P
break; 5!NK
} jx+%X\zokA
} 9#@dQ/*
else X-e)w
break; khyn4
} OtrO"K
} GNT1FR
catch(IOException e){e.printStackTrace ();} W,}HQ
catch(Exception e){e.printStackTrace ();} S6`4&0'
P}KyT?X:
Wu,'S;>C
Utility.log(nFileLength); 8m2-fuJz
7fgA)dU:K
a)`b;]+9
return nFileLength; uy9k^4Cqa
} )R<hYd
rH8w||S2U
O)kC[e4
//保存下载信息（文件指针位置） CY<,p$
private void write_nPos() ?*tb|AL(R
{ fj[B,ua
try{ ? !MDg_oHd
output = new DataOutputStream(new FileOutputStream(tmpFile)); "Rf8#\Y/<
output.writeInt(nStartPos.length); I?.$
for(int i=0;i<nStartPos.length;i++) I;S[Ft8d
{ 2a3hm8%U
// output.writeLong(nPos); g PU|Gv5
output.writeLong(fileSplitterFetch.nStartPos); KLGhsx35
output.writeLong(fileSplitterFetch.nEndPos); .:B] a7b
} .nJErC##
output.close(); ?a+tL'D[
} (A}##h
catch(IOException e){e.printStackTrace ();} FYFP6ti
catch(Exception e){e.printStackTrace ();} }H&NR?Ax
} Ix93/FAn
hw:zak#j,
<]r.wn=}M
//读取保存的下载信息（文件指针位置） hu%UEB
private void read_nPos() }eXzs_
{ \Azl6`Em
try{ 2$. ubA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yQ?N*'}$
int nCount = input.readInt(); kL 6f^MoL
nStartPos = new long[nCount]; HF" v \
nEndPos = new long[nCount]; ?%J{1+hY
for(int i=0;i<nStartPos.length;i++) ?"]fGp6y
{ E)DdiB'Rh
nStartPos = input.readLong(); <03@cs
nEndPos = input.readLong(); ~@S5*(&8
} WBFG_])
input.close(); gQ%'2m+
} HaXlc8
catch(IOException e){e.printStackTrace ();} ;aExEgTq
catch(Exception e){e.printStackTrace ();} AdxCP\S&
} e;5n.+m
JhRXfIK>{
* xdS<
private void processErrorCode(int nErrorCode) -yHVydu=
{ D *RF._
System.err.println("Error Code : " + nErrorCode); 2cY7sE068
} -g(&5._,ZW
QkBT,c
<"Z]S^>$
//停止文件下载 p&ytUTna
public void siteStop() )eop:!m
{ !:PF |dZ
bStop = true; ~gQ$etPd
for(int i=0;i<nStartPos.length;i++) s,XKl5'+8e
fileSplitterFetch.splitterStop(); -&I%=0q
s7e)Mt
*9M 5'
} 3&.?9
} t<mT=(zt*
//负责部分文件的抓取 [0U!Y/?6lA
**FileSplitterFetch.java ,rVm81-2
*/ 5<\&7P3y
package NetFox; iK8aj)%Q@
/_}xTP"9
_\waA^ F
import java.io.*; ":EfR`A#
import java.net.*; zim]3%b*A;
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k_?xiOSh
public class FileSplitterFetch extends Thread { 12BTZ
N+%E=D>
W}p>jP}
String sURL; //File URL @ de_|*c
long nStartPos; //File Snippet Start Position :c3}J<Z
long nEndPos; //File Snippet End Position q'~?azg:
int nThreadID; //Thread's ID F!OVx<
boolean bDownOver = false; //Downing is over 8##-fv]
boolean bStop = false; //Stop identical c+chwU0W
FileAccessI fileAccessI = null; //File Access interface ( P|Ph
}mQ7N&cC
%>Z;/j|#r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hf!o6 o
{ b)RU+9x &
this.sURL = sURL; k?ubr)[)
this.nStartPos = nStart; :#W40rUb
this.nEndPos = nEnd; LN}eD\
nThreadID = id; ]7" W(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pwAawm
} K0$8t%Z.
'X&sH/>r
.O!JI"?
public void run() ;/?M&rX
{ Z]f_?@0
while(nStartPos < nEndPos && !bStop) Y^DS~CrM
{ Si#I^aF`%
{`5Sh1b
`t_S uZ`V
try{ @b[{.mU
URL url = new URL(sURL); ]G.ttfC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (3 xCW
httpConnection.setRequestProperty("User-Agent","NetFox"); *ub]M3O
String sProperty = "bytes="+nStartPos+"-"; Ojqbj0E9
httpConnection.setRequestProperty("RANGE",sProperty); AuIb>@a
Utility.log(sProperty); L&V;Xvbu%
Pqiw[+a$
x_Zi^]
InputStream input = httpConnection.getInputStream(); w@w(AFV9/
//logResponseHead(httpConnection); Sc03vfmo"N
`kb]tf
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byte[] b = new byte[1024]; g-`HKoKe
int nRead; 4FSA:]o-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rMRM*`Q2
{ OUCLtn\
nStartPos += fileAccessI.write(b,0,nRead); `x%v&>
//if(nThreadID == 1) 1@Abs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u[nx?!
} /@Qg'Q#
So>P)d$8+
egQB!%D
Utility.log("Thread " + nThreadID + " is over!"); *J[3f]PBmR
bDownOver = true; Bk,:a,
//nPos = fileAccessI.write (b,0,nRead); #ra"(/)
} AX6z4G
catch(Exception e){e.printStackTrace ();} 533n z8&9@
} ' >a(|
} :|cC7,S
n0|oV(0FE
kA3nhBH
//打印回应的头信息 #oBMA
public void logResponseHead(HttpURLConnection con) eeKErpj8A
{ DmDsn
for(int i=1;;i++) 7&oT}Z
{ pxm{?eBz
String header=con.getHeaderFieldKey(i); `/]Th&(5
if(header!=null) P<<?7_ ??
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g\9I&z~?
Utility.log(header+" : "+con.getHeaderField(header)); "rhU2jT=c
else CjtBQ5
break; qm RdO R
} :cDhqBMNr`
} F3BWi[Xh
j1/.3\
poJ7q (
public void splitterStop() PL+r*M%ll
{ Md!L@gX6<
bStop = true; J<K-Yeph
} 3FWl_d~uD
-M]NdgI
p)_v.D3i
} lw/zgR#|
;F>$\"aG
&.dC%
/* ly,3,ok
**FileAccess.java 5Q_T=TL
*//文件访问(定位，写) -P I$SA,
package NetFox; ~Sq!P
import java.io.*; oW0A8_|9
|%wgux`z
&x~&]
public class FileAccessI implements Serializable{ LW+a-i
lr>:S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t(<^of:
RandomAccessFile oSavedFile; 4 h}03 oG
long nPos; XctSw
j=raS
aT9+] Ig
public FileAccessI() throws IOException 977%9z<h
{ N)F&c!anh
this("",0); 2Fi~GY_
} k,)xv?
)<J|kC\r6c
M%*D}s-QE
public FileAccessI(String sName,long nPos) throws IOException s& INcjC
{ yH\3*#+
oSavedFile = new RandomAccessFile(sName,"rw"); [w0@7p"7
this.nPos = nPos; )@vhqVv?
oSavedFile.seek(nPos); Qqp_(5S|>
} ,F&TSzH[@v
l|, Hj
c"nowbf
public synchronized int write(byte[] b,int nStart,int nLen) AXnuXa(j
{ }01c7/DRP<
int n = -1; &U_YDUQ'L
try{ HDmjt+3&n
oSavedFile.write(b,nStart,nLen); 8R3x74fL
n = nLen; gdPPk=LD
} Dd:TFZo
catch(IOException e) fGeDygV^`
{ > whcZ.8
e.printStackTrace (); i6S5 4&^!
} {D6p?TL+
JAQ y
5Kadh2nz
return n; `u<\ 4&W
} fbTq?4&Q
?S*Cvr+=4
65%WjO
} Az+k8=?
KF4D)NM|
Ipp#{'Do
/* %9q]
**SiteInfoBean.java p\'0m0*
*/ K@f@vyw]
package NetFox; As}eI!
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jkQ%b.a
public class SiteInfoBean { yb-1zF|
6>yfm4o
]+"25V'L
private String sSiteURL; //Site's URL a-cLy*W,~
private String sFilePath; //Saved File's Path (&B`vgmb
private String sFileName; //Saved File's Name \&6^c=2=
private int nSplitter; //Count of Splited Downloading File #JAy
~6Xr^An/Z
5LF&C0v
public SiteInfoBean() tk5zq-/d
{//nSplitter的缺省值为5 !y$:}W?_
//default value of nSplitter is 5 TQ,KPf$0U
this("","","",5); f`gs/R
} j;MQ_?"iN
2Y7u M;8
%tE#%;Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U.GRN)fL4
{ d:L|BkQ7*
sSiteURL= sURL; ^H(,^cVN
sFilePath = sPath; .eHOG]H
sFileName = sName; lEYAq'=
this.nSplitter = nSpiltter; ${F4x"x
P3k@ptc-K
rqi/nW
} /Xm4%~b_gj
ubQbEv{(,
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public String getSSiteURL() c-y`Hm2"
{ Wb%t6N?
return sSiteURL; Ncr*F^J4
} g}OZ!mKd
a/{M2
A-&XgOL
public void setSSiteURL(String value) )j+G4
{ KNG7$icG
sSiteURL = value; .Cz9?]jyI
} >X_5o^s2s
\0fk^
h0aK}`/a
public String getSFilePath() pGdFeEkB/
{ [vTk*#Cl4
return sFilePath; m>9j dsqB
} DLH|y%"
L}\ oFjVju
!Z!X]F-fY
public void setSFilePath(String value) He)!Ez\X
{ H7{I[>:
sFilePath = value; !T"jvDYH
} )>(ZX9diV
x~u"KU2B
>e^^YR^
public String getSFileName() WD>z
{ 80%L!x|
return sFileName; +`f3_Xd
} Q#5~"C
Q*ixg$>
O?$]/d
public void setSFileName(String value) )?;+<,
{ #Dp]S,e
sFileName = value; -oT3`d3
} wE3fKG.
WRp0.
FWW*f _L
public int getNSplitter() %+iAL<S
{ P?hB`5X
return nSplitter; Wi@YJ
} !LJ4 S
mRIBE9K+&
>0JCu^9
public void setNSplitter(int nCount) qH(HcsgD
{ q.bxnta"
nSplitter = nCount; )I"I[jDw
} :n,x?bM
} 8GeJ%^0o}
7U!-_)n{
w!jY(WKU
/* "hnvND4=
**Utility.java {dYz|O<
*/ lS]6SkZ6
package NetFox; tYp 185
biPj(Dd
)jjL'
public class Utility { 2B"tT"f
_p'u!.a?!
w:ASB>,!
public Utility() 48Jt1^
{ |G/U%?`
LkWY6 ?$U
HWFLu
} &crR nv?
ECk3Da
//线程睡眠 Dq-[b+bm
public static void sleep(int nSecond) 1DlXsup&?#
{ &3Lhb}m
try{ )J?8"+_Y
Thread.sleep(nSecond); \Vpv78QF;
} ^kke
catch(Exception e) PZVH=dagq
{ BIEq(/-
e.printStackTrace (); _WZ{i,
} tRo` @eEX
} ]Upr<!
)q`.tsR>
//日志 Wt.['`c<
public static void log(String sMsg) aQ-SrxmO8
{ RKZBI?@4
System.err.println(sMsg); ]WK~`-3C^
} V.ETuS;
jO9!:L>b`
?*.:*A
public static void log(int sMsg) _ ^'QHWP
{ T-h[$fxR_
System.err.println(sMsg); [930=rF*
} YP[8d,
} UCj:]!P
VK!HuO9l
P 5.@LN
/* U "r)C;5
**TestMethod.java 5gkQ6&m
*/ o_BRsJy
package NetFox; t|s(V-Wq
fhyoSRLR:
abv*X1
public class TestMethod { 9m)gp19YA
*U}-Y*
&3J^z7kU
public TestMethod() t/_\w"
{ ///xx/weblogic60b2_win.exe B`||4*
try{ y}is=h3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l-Ha*>gX[j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IVy<>xpt
SiteFileFetch fileFetch = new SiteFileFetch(bean); X,Rl&K\b"
fileFetch.start(); a:OMI
} !X||ds
catch(Exception e){e.printStackTrace ();} >?_}NZ,y
+XSe;xk;rD
o5sw]R5
} _q}Cnp5
1wH6 hN,
n).*=YLN
public static void main(String[] args) OjNOvh&N
{ NEPK
new TestMethod(); R4T@ ]l&W
} WnOvU<Z <
} D?UURURf
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