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)); 1_;{1O+B
} *(5T?p[7
for(int i=0;i<nEndPos.length-1;i++) D#`>p
{ C9""sVs
nEndPos = nStartPos[i+1]; v046
} -0]%#(E%`h
nEndPos[nEndPos.length-1] = nFileLength; ?1O` Rd{tn
} 62Tel4u
} xpu2RE
f<|*^+
jY=M{?h''
//启动子线程 ~J5B?@2hK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C(z'oi:f
for(int i=0;i<nStartPos.length;i++) ?<\2}1
{ Nz*,m'-1e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -II03 S1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l[%=S!
nStartPos,nEndPos,i); Lp4F1H2t-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lOe|]pQ.,
fileSplitterFetch.start(); P*U^,Jh<
} nqTOAL9FF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;i/? fw[h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZSD7%gE<D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oQ*LP{M
nEndPos = " + nFileLength); a0PU&o1EF
// fileSplitterFetch[nPos.length-1].start(); \[)SK`cwd
VeY&pPQ
l]Ym)QP
//等待子线程结束 !h<O c!9
//int count = 0; }s6Veosl
//是否结束while循环 CBpwtI>p
boolean breakWhile = false; G+k wG)K
>LH}A6dUC
&RI;!qn6(
while(!bStop) R9"}-A
{ ]$sb<o .a
write_nPos(); 23,pVo
Utility.sleep(500); J6>tGKa+e
breakWhile = true; _%\%
kd]CV7(7
yx*<c#Uf
for(int i=0;i<nStartPos.length;i++) bGy|T*@
{ @t*D<B$
if(!fileSplitterFetch.bDownOver) ukc 7Z OQ
{ Tow!5VAM
breakWhile = false; ~_F;>N~
break; T(]*jaB
} 0*oavY*
} l%?4L/J)#
if(breakWhile) ylS6D
break; guf*>qNr
)^"V}z t
Dfc% jWbA
//count++; 2+C:Em0yI
//if(count>4) ;4GGXT++L
// siteStop(); f4F%\ "
} 19pFNg'kA
.5s^a.e'O
3c(mZ
System.err.println("文件下载结束！"); qK2jJ3)>
} Hi/[
catch(Exception e){e.printStackTrace ();} V\e1NS
} 0S'@(p[A
~Cg7
PX2b(fR8_O
//获得文件长度 ;O{bF8U
public long getFileSize() h+Yd \k
{ `_i|\}tl
int nFileLength = -1; 5ug|crX
try{ j(K)CHH
URL url = new URL(siteInfoBean.getSSiteURL()); FUJ<gqL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rwio>4=
httpConnection.setRequestProperty("User-Agent","NetFox"); $/@ L
ZJF+./vN
`g)
int responseCode=httpConnection.getResponseCode(); Tr|PR t
if(responseCode>=400) HVhd#Q;
{ UugR
processErrorCode(responseCode); K=}Eupn=
return -2; //-2 represent access is error qbCU&G|)
} f1elzANy
:PY6J}:&#
7zA+UWr
String sHeader; [u^ fy<jdp
{.[EXMX
J|^z>gP(
for(int i=1;;i++) mh`uvqY
{ ur=:Ha
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zxH<~2
//Utility.log(in.readLine()); 0 z]H=
sHeader=httpConnection.getHeaderFieldKey(i); JP5en
if(sHeader!=null) UIg?3J}R
{ C]l)Pz$
if(sHeader.equals("Content-Length")) bmi",UZ:F
{ yHlQKI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 11Qi _T\
break; aJF/y3
} ~ qaT jSP
} *tk=DsRW
else ;*9<lUvu
break; >j$aY
} i_*.
} p5w9X+G%
catch(IOException e){e.printStackTrace ();} #Ufb
catch(Exception e){e.printStackTrace ();} 1[#sHj$Na`
J=(i0A
Bgzq
Utility.log(nFileLength); uudd'L
J7%rPJ
5} ur,0{
return nFileLength; <sM_zoprc
} U>bIQk"4
.a(G=fk
}$qrNbLJ
//保存下载信息（文件指针位置） skTaIGRL
private void write_nPos() r$'.$k\
{ *O@Zn
try{ !b4AeiL>w
output = new DataOutputStream(new FileOutputStream(tmpFile)); Qp)?wny4
output.writeInt(nStartPos.length); |`Yn'Mj8rm
for(int i=0;i<nStartPos.length;i++) tX@y ]"
{ _T~&kwe
// output.writeLong(nPos); VAUd^6Xdwx
output.writeLong(fileSplitterFetch.nStartPos); I>vU;xV\m
output.writeLong(fileSplitterFetch.nEndPos); ggkz fg&
} u^c/1H:6
output.close(); XeY[;}9
} {D|ST2:E
catch(IOException e){e.printStackTrace ();} X&5N89
catch(Exception e){e.printStackTrace ();} Q=vo5)t
} br 3-.g
ycki0&n3
,`!lZ| U
//读取保存的下载信息（文件指针位置） 02tN=}Cj)
private void read_nPos() -aE,KQ
{ F9r/ M"5
try{ F$|:'#KN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;mz#$"(
int nCount = input.readInt(); F2_'U' a
nStartPos = new long[nCount]; h8Oj E$ H
nEndPos = new long[nCount]; J(maJuY
for(int i=0;i<nStartPos.length;i++) y;4g>ma0
{ 3 Fy CD4#
nStartPos = input.readLong(); H.C*IL9
nEndPos = input.readLong(); +Zr~mwM=x
} 4KSq]S.
input.close(); :[f[-F
} +~of#
catch(IOException e){e.printStackTrace ();} !+z^VcV
catch(Exception e){e.printStackTrace ();} #Cy3x-!
} )+8r$ i
#Dz"g_d
p1i}fGS
private void processErrorCode(int nErrorCode) cC|
{ V*(x@pF
System.err.println("Error Code : " + nErrorCode); ahCwA}
} fkX86
iS<1C`%>
UWS 91GN@
//停止文件下载 m-;8O /
public void siteStop() >=:mtcph
{ M6qNh`+HO
bStop = true; F1B/cd
for(int i=0;i<nStartPos.length;i++) Q*1'k%7
fileSplitterFetch.splitterStop(); *icaKy3
q _K@KB
QJiH^KY6
} x5pu+-h
} F$1{w"&
//负责部分文件的抓取 a_{'I6a*,
**FileSplitterFetch.java C!+PBk[9
*/ tX1`/}``
package NetFox; )\2KDXc
/38I(0
77aUuP7Iw
import java.io.*; f?GoBh<
import java.net.*; $ve$Sq
i[FYR;C
tSoF!@6
public class FileSplitterFetch extends Thread { y:$qX*+9e
9,\AAISi
q+<,FdG
String sURL; //File URL $?gKIv>g
long nStartPos; //File Snippet Start Position r2i]9>w
long nEndPos; //File Snippet End Position /YJBRU2
int nThreadID; //Thread's ID J&JZYuuf
boolean bDownOver = false; //Downing is over @W @,8e]c
boolean bStop = false; //Stop identical zw$\d1-+h
FileAccessI fileAccessI = null; //File Access interface mJ5%+.V
Iw( wT_
Knb(MI6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b2[U3)|oO
{ OkISRj'!U
this.sURL = sURL; yI07E "9
this.nStartPos = nStart; Fn4yx~0
this.nEndPos = nEnd; O:T 49:R}r
nThreadID = id; |*h{GX.(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |]?W`KN0
} 8f)pf$v`
fi~@J`
)t7MD(
public void run() GVn'p Wg
{ 7 <]YK`a2d
while(nStartPos < nEndPos && !bStop) n6Uf>5
{ < ]+Mdy
wmXI8'~F&
z-g6d(
try{ ;1nXJ{jKw
URL url = new URL(sURL); gN[t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~!7x45(1#
httpConnection.setRequestProperty("User-Agent","NetFox"); ]>k8v6*=
String sProperty = "bytes="+nStartPos+"-"; ;/?w-)n?
httpConnection.setRequestProperty("RANGE",sProperty); t>*(v#WeZ
Utility.log(sProperty); 3W#E$^G_v
!^0vi3I
nec}grA
InputStream input = httpConnection.getInputStream(); Z0y~%[1X
//logResponseHead(httpConnection); g=qaq
/iQh'rp
0CXXCa7!
byte[] b = new byte[1024]; `r3 klL,W'
int nRead; bXXX-Xc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QV\af
{ 6o9&FU
nStartPos += fileAccessI.write(b,0,nRead); /z`tI
//if(nThreadID == 1) \{~CO{II
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dvZlkMm
} k2,`W2]^E
eK*oV}U-k
K4]ZVMm/*
Utility.log("Thread " + nThreadID + " is over!"); 5|Z8UzL
bDownOver = true; F!/-2u5gF
//nPos = fileAccessI.write (b,0,nRead); O#O"]A
} $ #GuV'
catch(Exception e){e.printStackTrace ();} yuJ>xsM
} /0fsn_
} ;E.f%
n$7*L9)(C
NW3qs`$-(
//打印回应的头信息 )flm3G2u
public void logResponseHead(HttpURLConnection con) fB,eeT1v?h
{ $ywROa]
for(int i=1;;i++) 9b,0_IMHH
{ 8tna<Hx
String header=con.getHeaderFieldKey(i); /7p(%vr
if(header!=null) 41+WIa L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l`:u5\ rM
Utility.log(header+" : "+con.getHeaderField(header)); 1ZYo-a;)
else T:2f*!r
break; 3k(tv U+eC
} ?K2}<H-
} cTRtMk%^
QUvSeNSp
g"Ueo'd*
public void splitterStop() c$BH`" <*
{ t?Qbi)T=z
bStop = true; BtKor6ba
} Hy,""Py
h7TkMt[l
+Ig%h[1a
} *fv BB9raq
Fo;:GX,b
,RY;dX-#
/* c|aX4=Z
**FileAccess.java W(4$.uZ)
*//文件访问(定位，写) g.%} +5
package NetFox; CQa8I2VF (
import java.io.*; cjO%X
.sM,U
bqA`oRb\
public class FileAccessI implements Serializable{ -Eq[J k
`#8kJt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l Ib d9F
RandomAccessFile oSavedFile; `^'fS@VA
long nPos; *jPd=+d
In1n.oRFn^
)s,tBU+N
public FileAccessI() throws IOException ST?Rl@4
{ 2cIKph
this("",0); 5kQ@]n:<k
} yqL"YD
kTI5CoXzq
Q3^h
public FileAccessI(String sName,long nPos) throws IOException S^p^) fAmF
{ $@] xi
oSavedFile = new RandomAccessFile(sName,"rw"); ZnzO]
this.nPos = nPos; FkuD Gg~a
oSavedFile.seek(nPos); >qr/1mW
} [{GN#W|AGP
='4)E6ea?
qz3 Z'
public synchronized int write(byte[] b,int nStart,int nLen) chKEGosbF
{ |K{d5\_
int n = -1; c?. i;4yh
try{ w%X@os}E
oSavedFile.write(b,nStart,nLen); ]$9y7Bhj.
n = nLen; (S+/e5c)
} JR15y3F
catch(IOException e) -@`Ah|m@}
{ HQ7g0:-^a>
e.printStackTrace (); |mHf7gCX
} oD\t4]?E
yTK3eK
cqJXZ.XC
return n; Aaq%'07ihW
} I=<Qpd4
i '*!c
n^hkH1vY
} >1Hv c7DP
8zlvzp
2\z|/ Q
/* dW!El^w}
**SiteInfoBean.java "M[&4'OM
*/ zp}pS2DU
package NetFox; ]adgOlM
ry=8Oq&[~
L*,h=#x(
public class SiteInfoBean { H&p:
Qox/abC h
A s}L=2
private String sSiteURL; //Site's URL dhnX\/
private String sFilePath; //Saved File's Path !y/e Fx
private String sFileName; //Saved File's Name vazA@|^8
private int nSplitter; //Count of Splited Downloading File Y`eF9Im,
"!AtS
=SeQ- H#
public SiteInfoBean() !o?&{"#+
{//nSplitter的缺省值为5 jIrfJ*z
//default value of nSplitter is 5 $':5uU1}
this("","","",5); T|D^kL%m!
} jN*wbqL
{J,"iJKop
^0}wmxDq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) js Z"T
{ RN[x\",
sSiteURL= sURL; lMu-,Z="
sFilePath = sPath; 5Ww,vSCV)
sFileName = sName; M/9[P* VE
this.nSplitter = nSpiltter; \<T7EV.
H?Q--pG8
hE`d@
} !z4I-a
sZr \mQ~
}[UH1+`L
public String getSSiteURL() pL;e(lM
{ 7.ein:M|CB
return sSiteURL; V59!}kel1%
} Db*b"/]
Y,}h{*9Kd
cNmAr8^}
public void setSSiteURL(String value) R13k2jLSQ
{ JeNX5bXW
sSiteURL = value; % 33O)<?
} pt3)yj&XE
DeNWh2
Fv %@k{
public String getSFilePath() ?6&G:Uz/
{ U>.5vK.+
return sFilePath; p!=8Pq.
} [hg9 0Q6
Kg>B$fBx)
YlG#sBzl
public void setSFilePath(String value) L xIKH G
{ F02TM#Zi
sFilePath = value; O|=?!|`o
} @d|Sv1d%
cQThpgha
O{\<Izm`D
public String getSFileName() VBDb K|
{ <D)@;A
return sFileName; o&@y^<UQ
} <bg6k .s
XP}5i!}}7=
2YWO'PL
public void setSFileName(String value) qM26:kB{
{ Pp69|lxV=k
sFileName = value; .*oL@iX
} 1D8S}=5&
CPcUB4a%#
%@)q=*=y
public int getNSplitter() ONcLhwH
{ *?uUP
return nSplitter; ;'V[8`Z@
} i>CR{q
Ti0kfjhX7
!.O[@A\.-
public void setNSplitter(int nCount) K,|3?CjS
{ GIpYx`mHi
nSplitter = nCount; y&8`NS#_p?
} -@#],s7
} <kwF<J
t5K#nRd Z:
_:tS-Mx@5
/* A&v Qtd
**Utility.java 9IG<9uj
*/ (0LA.aBIf
package NetFox; h@ ZC{B
#Y-_kQV*
*)^ZUk
public class Utility { d$+0;D4E
dJ])`S
i(.PkYkaq
public Utility() Ev [?5R
{ <im}R9eJ1
#>lbpw
( )ldn?v
} l,b,U/3R.
,H/O"%OJ
//线程睡眠 rOEBL|P0
public static void sleep(int nSecond) :KG=3un]
{ tCR~z1
try{ m3P7*S5NJ7
Thread.sleep(nSecond); ,f,+)C$
} b.[9Adi >
catch(Exception e) }.9a!/@Aj
{ hH;i_("i(h
e.printStackTrace (); zIS ,N '
} xnWezO_
} MwSfuP
0~WXA=XG
//日志 Bv3B|D&+
public static void log(String sMsg) `H*mQERb
{ +=|%9%
System.err.println(sMsg); 09Eg ti.
} lcReRcjm
]=xX_
&vN!>bR
public static void log(int sMsg) 2Y[n
{ E U RKzJk
System.err.println(sMsg); -p7 HQ/
} 3&M0@/
} oPbziB8
w7pX]<?R"
edlf++r~
/* J n2QvUAZ&
**TestMethod.java \' A- Lp
*/ j%]sym
package NetFox; R!X+-
gCkR$.-E
ZDI?"dt{
public class TestMethod { O6b+eS
?LU>2!jN
V7gL*,3>=
public TestMethod() eUR+j?5I
{ ///xx/weblogic60b2_win.exe N;!!*3a9=
try{ 8$iHd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |{ZdAr.;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bi@'m?XwJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); -T+'3</T
fileFetch.start(); Nqd9)WQ
} +`B^D
catch(Exception e){e.printStackTrace ();} !a!4^zqp
*u,&?fCl
I7Abf7>*Q
} 5t_Dt<lIz
6iEg]FI
@/$i -?E
public static void main(String[] args) y[S9b(:+
{ yqtHlz%
new TestMethod(); unz~vG1Tn
} .V_5q:tu
} Z:x`][vg
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