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)); HK?Foo?
} `}ZL'\G
for(int i=0;i<nEndPos.length-1;i++) WE7>?H*Ro
{ R,XD6'Q
nEndPos = nStartPos[i+1]; bf{Ep=-
} 9/^d~ZO
nEndPos[nEndPos.length-1] = nFileLength; we @Yw6<
} [!5l0{0
} 3k`NNA
jw/wcP
9.jG\i
//启动子线程 xvHOY:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "_Zh5 g
for(int i=0;i<nStartPos.length;i++) mJ/^BT]
{ p~ mN2x]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :0{AP_tvcC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -<_+-t
nStartPos,nEndPos,i); ))$ CEh"X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *?s/Ho &'
fileSplitterFetch.start(); (1OW6xtfG
} j`Tm\!q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #dL5x{gV=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uTxX`vH@!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I<IC-k"Y
nEndPos = " + nFileLength); McO@p=M
// fileSplitterFetch[nPos.length-1].start(); 9j9YQ2
O#A8t<f|M
0,+EV,
//等待子线程结束 "Fo
//int count = 0; rE9Ta8j6
//是否结束while循环 3{I=.mUUm
boolean breakWhile = false; wrhBH;3
:A,O(
e?|d9;BO
while(!bStop) 5R&x{jf$
{ &%@/Dwr
write_nPos(); wbn^R'
Utility.sleep(500); ?]759,Q3L
breakWhile = true; ;B,nzx(L
$gXkx D
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for(int i=0;i<nStartPos.length;i++) +!D=SnBGs
{ tuX =o
if(!fileSplitterFetch.bDownOver) @#'yPV1
{ z&\Il#'\m+
breakWhile = false; {(8U8f<'=y
break; YWybPD4\(
} gF$1wV]e
} !k4 }v'=
if(breakWhile) AEiWL.*.
break; SjFF=ib
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yIn/Y0No
//count++; gNG0k$nP
//if(count>4) vsOdp:Yp9!
// siteStop(); eV@4VxaZ
} kq-mr
g|_HcaW
$1:}(nO,
System.err.println("文件下载结束！"); 9[6G8;<D&
} _Ac/ir[,:
catch(Exception e){e.printStackTrace ();} WK/b=p|#o
} f>.`xC{
v)wY
FF5tPHB
//获得文件长度 6:e}v'q{
public long getFileSize() nL "g23
{ kxt\{iy4
int nFileLength = -1; 9/@FADh
try{ ~Rx~g
URL url = new URL(siteInfoBean.getSSiteURL()); z36brv<_'p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PmuEL@'^ U
httpConnection.setRequestProperty("User-Agent","NetFox"); N` @W%
7-g]A2N
$%N;d>[U,
int responseCode=httpConnection.getResponseCode(); u&hDjE
if(responseCode>=400) 9Ba%=
{ F(?Fz8
processErrorCode(responseCode); [,.[gWA
return -2; //-2 represent access is error Vu_7uSp,)
} My'9S2Y8nv
v9X7-GJ~
`</=AY>
String sHeader; LZ=wz.'u
<(u3+`f1s
iX0]g45o
for(int i=1;;i++) }z9I`6[
{ 7UeE(=Hr5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,n /SDEL
//Utility.log(in.readLine()); )&b}^1
sHeader=httpConnection.getHeaderFieldKey(i); LS R_x$G+t
if(sHeader!=null) /h.:br?M#P
{ ~Hp#6+
if(sHeader.equals("Content-Length")) 48*Oh2BA
{ Gd]5xl HRU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #U\&i`
break; Huc3|~9
} YD0vfwh
} yBXkN&1=%;
else P>yG/:W;
break; Zi2Eu4p l{
} i} NkHEK
} Y&1!Z*OL;
catch(IOException e){e.printStackTrace ();} @'k,\$/
catch(Exception e){e.printStackTrace ();} vu !j{%GO
9XJ9~I?
.P|+oYT&g
Utility.log(nFileLength); ,u8ZS|9
{Oc?C:aI=
t(uB66(_F
return nFileLength; ~#IWM+I
} "Gi+zkVm
|g: '')>[
X-*KQ+?
//保存下载信息（文件指针位置） &"~,V6,q
private void write_nPos() .&* ({UM
{ mlsvP%[f.
try{ vkNZ -`+I
output = new DataOutputStream(new FileOutputStream(tmpFile)); p3,(*eZ
output.writeInt(nStartPos.length); n;S0fg
for(int i=0;i<nStartPos.length;i++) L:k@BCQM
{ 7>W+Uq
// output.writeLong(nPos); 9}'l=b:Jms
output.writeLong(fileSplitterFetch.nStartPos); O|^6UH
output.writeLong(fileSplitterFetch.nEndPos); 4X(1
} >h/)r6
output.close(); _^ CQ*+F
} <.?^LT
catch(IOException e){e.printStackTrace ();} z Et6
catch(Exception e){e.printStackTrace ();} :3E8`q~c1
} ;ZE<6;#3IP
^G7n#
RpaA)R,
//读取保存的下载信息（文件指针位置） $@ T6g
private void read_nPos() qw Kh,[]
{ gOES2 4$2
try{ ATXx? b8h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?=|)n%
int nCount = input.readInt(); 2S7H_qo$
nStartPos = new long[nCount]; m\}\RnZu
nEndPos = new long[nCount]; K_<lO,[S
for(int i=0;i<nStartPos.length;i++) Bcd0
{ >gS5[`xRE
nStartPos = input.readLong(); ;k63RNT,M&
nEndPos = input.readLong(); ] fwTi(4y
} pO7{3%
input.close(); 4/mj"PBKL
} vt(}ga
catch(IOException e){e.printStackTrace ();} F_M~!]<na
catch(Exception e){e.printStackTrace ();} +"N<-
} ~YT>:Np
>FEQtD~F
u}@%70A
private void processErrorCode(int nErrorCode) c-3YSrY
{ )n3biQL_
System.err.println("Error Code : " + nErrorCode); 4%c7#AX[T
} B9;,A;E};
9cw4tqTm
?SsRN jeL
//停止文件下载 S*DBY~pZy
public void siteStop() x/jN&;"/
{ Do[ F+Y
bStop = true; zvQ^f@lq2
for(int i=0;i<nStartPos.length;i++) Sj]T{3mi
fileSplitterFetch.splitterStop(); D.oS8'
R(7X}*@X
|]2eGrGj4
} 3Oig/KZ
} 2}xFv2X
//负责部分文件的抓取 |Z^c#R
**FileSplitterFetch.java s_Ge22BZ
*/ 1+PNy d
package NetFox; E#HU?<q8
_>:=<xyOq
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import java.io.*; :BZx)HxQ
import java.net.*; oRJP5Y5na
;Cp/2A}Xx
[2H(yLwO
public class FileSplitterFetch extends Thread { N-?|]4e/
4[f7X4d$
xx`8>2T#e
String sURL; //File URL #*;fQ&p
long nStartPos; //File Snippet Start Position me}Gb a
long nEndPos; //File Snippet End Position C{I8Pio{b
int nThreadID; //Thread's ID c_8mQ
boolean bDownOver = false; //Downing is over ;HLMU36q
boolean bStop = false; //Stop identical <J_,9&\J
FileAccessI fileAccessI = null; //File Access interface w\8rh\Mvh
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efAahH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }RP9%n^
{ n-| i
this.sURL = sURL; ]@<3 6ByM
this.nStartPos = nStart; :Ro" 0/d
this.nEndPos = nEnd; RxDxLU2kt
nThreadID = id; yfw>y=/p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RT+30Q?
} %RD7=Z-z
BQfAen]
Jv{"R!e"P
public void run() 0f#a_
{ <T2~xn
while(nStartPos < nEndPos && !bStop) R7;rBEt8
{ Z_4H2HseL
uRq#pYn@
Er+3S@sfq,
try{ s?\9i6
URL url = new URL(sURL); fOjt` ~ToI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $q@RHcj
httpConnection.setRequestProperty("User-Agent","NetFox"); )eGu4iEPM
String sProperty = "bytes="+nStartPos+"-"; 02c.;ka3
httpConnection.setRequestProperty("RANGE",sProperty); yW=hnV{
Utility.log(sProperty); `R=_t]ie
9oau_Q#
)1yUV*6
InputStream input = httpConnection.getInputStream(); D!E 9@*Lf
//logResponseHead(httpConnection); ]B.,7
G`JwAy r'
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byte[] b = new byte[1024]; g#<?OFl
int nRead; = ]HJa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &T/9yW[L
{ -0J<R;cVs
nStartPos += fileAccessI.write(b,0,nRead); j]F3[gpc
//if(nThreadID == 1) LGgx.Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q_|S^hxQ
} \w\47/k{
Va[dZeoy
`&Of82*w
Utility.log("Thread " + nThreadID + " is over!"); aKU8" 5
bDownOver = true; cM'[;u
//nPos = fileAccessI.write (b,0,nRead); }PD(kk6fX
} Gqz)='
catch(Exception e){e.printStackTrace ();} J<:D~@qq
} :bF2b..XOu
} %|6Q7'@p
3'@jRK
>U Ich
//打印回应的头信息 g:6}zHK
public void logResponseHead(HttpURLConnection con) ]X;*\-
{ g<0%-p
for(int i=1;;i++) LFM5W&?
{ (IQ L`3f%
String header=con.getHeaderFieldKey(i); XK9*,WA9r
if(header!=null) R\=\6("
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 52R.L9Ai
Utility.log(header+" : "+con.getHeaderField(header)); RuEnr7gi
else *wZV*)}
break; -EIMh^
} hnLgsz
} 7}7C0mV3
BCDf9]X
]qG5Ne_
public void splitterStop() n~cm?"
{ <yaw9k+P
bStop = true; IG@&l0ARL
} 0_Z|y/I.
Jy[8,X
aZ0iwMK
} E6\~/=X=%
[?o vJ
{'bkU9+
/* )s[S.`STz
**FileAccess.java H4",r5qw:
*//文件访问(定位，写) 6#63D>OWp
package NetFox; 4U1fPyt
import java.io.*; [*E.G~IS`
:v ~q
~l(tl[
public class FileAccessI implements Serializable{ B9Tztg
\B+SzW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oa|*-nw
RandomAccessFile oSavedFile; weadY,-H8
long nPos; _@?Jx/`;bk
03\8e?$
90k|u'ikOp
public FileAccessI() throws IOException rSCX$ @@F
{ `%:(IGxz
this("",0); Yzx0[_'u
} >V=@[B(0
*J5euA5=
"r3s'\
public FileAccessI(String sName,long nPos) throws IOException jmVy4* P_
{ \(t>(4s_~
oSavedFile = new RandomAccessFile(sName,"rw"); W%QtJB1)
this.nPos = nPos; D??/=`|8
oSavedFile.seek(nPos); Gf.o{
} #u(,#(P'#
AdW7 vn
X.5LB!I)
public synchronized int write(byte[] b,int nStart,int nLen) p arG
{ eV}Tx;1|}
int n = -1; RxG./GY
try{ @n'ss!h
oSavedFile.write(b,nStart,nLen); N2Hb19/k
n = nLen; \`# 0,pLr
} HBGA lZ
catch(IOException e) Upen/1bA
{ S*@0%|Q4r
e.printStackTrace (); U MIZ:*j
} T<GD!j(
.Q@'Ob`
V2skr_1
return n; [)c|oh%
} 84cH|j`w
=i %w_e
RL8wSK
} ?saVk7Z[|5
Ka2tr]+s
<cjTn:w
/* aBLb i
**SiteInfoBean.java L#bQ`t
*/ ay[*b_f
package NetFox; Lwk-
bUL9*{>G
iP_Xr~w
public class SiteInfoBean { ^<+heX
^Z+D7Q
>1zzDd_
private String sSiteURL; //Site's URL p$v +L
private String sFilePath; //Saved File's Path ,KaWP
private String sFileName; //Saved File's Name EOC"a}Cq-
private int nSplitter; //Count of Splited Downloading File fdW={}~
ZM!~M>B9R
uMZf9XUE
public SiteInfoBean() W<l(C!{
{//nSplitter的缺省值为5 brot&S2P><
//default value of nSplitter is 5 T6#GlO)8)
this("","","",5); JFdzA
} [)u{-
:E*U*#h/
IBsn>*ja<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z_+No :F7I
{ `^{P,N>X
sSiteURL= sURL; CgE5;O
sFilePath = sPath; zf u78
sFileName = sName; (DAJ(r~
this.nSplitter = nSpiltter; 5)6%D
+06j+I
lNAHn<ht
} WQ`T'k#ESW
ij5YV3
KR0 x[#.*
public String getSSiteURL() %Ski5q
{ L\DaZ(Y
return sSiteURL; < Ifnf6~
} b*fflJ
![%,pip2/&
b"9,DQB=i
public void setSSiteURL(String value) N4-J !r@#~
{ ,iUx'U
sSiteURL = value; l0)uu4|
} #m>mYp8E.5
wYG0*!Vj
\>k+Oyj
public String getSFilePath() 7i/Cax
{ BZ9iy~
return sFilePath; "dTXT
} ~yN,FpD
{c;3$
dW68lVWq_
public void setSFilePath(String value) ]+P&Y:
{ W9"I++~f
sFilePath = value; =ndKG5
} ak[)+_k_
@( l`_Wx
O6]~5&8U.
public String getSFileName() W[s>TDc`v
{ AF6'JxG7
return sFileName; ba13^;fm#
} H=C;g)R
P+h&tXZn8
=@o}
public void setSFileName(String value) 63=m11Z4
{ (P-<9y@
sFileName = value; _(foJRr
} s=4.Ovd\
+&@0;zSga
UEUTu}4y
public int getNSplitter() ig{5]wZ(
{ -s"lW 7N^
return nSplitter; iXFaQ
} A$cbH.
h;->i]
-yeT$P&|
public void setNSplitter(int nCount) ZI7<E
{ 6tguy
nSplitter = nCount; c^y 1s*
} _rd{cvdR
} -}@9lhS,
{W]jVh p
xFZq6si?
/* s?Kn,6Y
**Utility.java }T,uw8?f!
*/ >YLm]7v}
package NetFox; v&n&i?
g%trGW3{-
@#apOoVW>
public class Utility { Sls> OIc
/Ny&;Y
+Sfv.6~v
public Utility() o6 /?WR9
{ Cmj)CJ-
q@:&^CS
LxT]-
} 3nO|A: t
n>WS@b/o
//线程睡眠 XJ;/kR
public static void sleep(int nSecond) 00i9yC8@6
{ (agdgy:#
try{ Xc!w y9m
Thread.sleep(nSecond); 3>+;G4
} mX89^
catch(Exception e) 9[`6f8S_$
{ :9}*p@
e.printStackTrace (); |wDCIHzQ
} n[@Ur2&)
} 9=|5-?^
!r<7]nwV
//日志 lK-I[i!
public static void log(String sMsg) PO&`rr
{ f@0`,
System.err.println(sMsg); c,@6MeKHq
} cF6|IlhO
duI8^&|
\cG'3\GI
public static void log(int sMsg) \1ZfSc
{ C7{wI`~
System.err.println(sMsg); x+pFu5,
} Ero3A'f
} o#i{/#oF
(rJvE*
Gkl#s7'
/* Ot?rsr
**TestMethod.java fOVRtSls
*/ xk/(|f{L
package NetFox; >L%%B-
DxlX-
{)mlXo(On
public class TestMethod { :|a[6Uwl\V
ydt1ED0Q-
QUt!fF@t
public TestMethod() 3r\QLIr L8
{ ///xx/weblogic60b2_win.exe ZU`"^FQ3A
try{ W>~V?%F&'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X\;y;pmRH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P.o W#Je
SiteFileFetch fileFetch = new SiteFileFetch(bean); .eE5pyw+C
fileFetch.start(); $)U RY~;i
} @9-qqU@
catch(Exception e){e.printStackTrace ();} 4t":WutC
1 !sYd@iD@
"P6MLf1
} /=N`P &R#
,0~=9dR
y.zW>Mfl
public static void main(String[] args) {}z7N~
{ r* U6govky
new TestMethod(); Z1Wra-g
} B4kIcHA
} O'k"6sBb
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