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)); .i )n1
} sEKF
for(int i=0;i<nEndPos.length-1;i++) :_F 8O
{ t@ri`?0w
nEndPos = nStartPos[i+1]; XR<g~&h
} ,dosF Q
nEndPos[nEndPos.length-1] = nFileLength; xY.?OHgG/
} *>:<
} J0f!+]~G3
=eS?`|
0dsL%G~/N
//启动子线程 xFIzq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s`G}MU
for(int i=0;i<nStartPos.length;i++) lSoAw-@At8
{ hW~UJ/$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <eS+3,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OXl0R{4
nStartPos,nEndPos,i); MOytxl:R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^R :zma
fileSplitterFetch.start(); oO7)7$|1
} ang~_Ec.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NYKYj`K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;gAL_/_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B7Zi|-F
nEndPos = " + nFileLength); BW3Q03SW6
// fileSplitterFetch[nPos.length-1].start(); b&Laxki
2dB]Lw@s
K:VZ#U(_
//等待子线程结束 h3GUFiZ.
//int count = 0; zmu+un"\j
//是否结束while循环 u|\?6fz
boolean breakWhile = false; Nw"?~"bo
;;C2t&(
uvR l`"Y
while(!bStop) x|c_(
{ Hj`\Fm*A
write_nPos(); cdGBo4
Utility.sleep(500); V_e
breakWhile = true; N9*QQ0
I\M }Dxpp
]Nssn\X7
for(int i=0;i<nStartPos.length;i++) TI2K_'
{ 2qVoe}F
if(!fileSplitterFetch.bDownOver) 0DnOO0Nc
{ j0Cj&x%qF}
breakWhile = false; zN)).a
break; oxUBlye
} py%~Qz%
} 'R-g:X\{
if(breakWhile) f`}/^*D
break; amX1idHo^
1D!MXYgm1b
WjSu4
//count++; @)!N{x?
//if(count>4) l&kZ6lZ
// siteStop(); &v;o }Q}E{
} W1LR ,:$
5G`fVsb
R>5Xv%R
System.err.println("文件下载结束！"); sX}#L
} ([^f1;ncm
catch(Exception e){e.printStackTrace ();} [}l 90lP
} FJKlqM5]
<R~;|&o,$
#W.vX=/*
//获得文件长度 paMK]-
public long getFileSize() Bva2f:)K|
{ sO(4F8cpU
int nFileLength = -1; VfDa>zV3
try{ nz#eJ
URL url = new URL(siteInfoBean.getSSiteURL()); [~G1Rz\h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vl+bc[ i~
httpConnection.setRequestProperty("User-Agent","NetFox"); L(k`1E
=:6B`,~C
u]`0QxvZ
int responseCode=httpConnection.getResponseCode(); yh|+Usa
if(responseCode>=400) 9:=:P>
{ je3Qq1
processErrorCode(responseCode); tJ8:S@E3,
return -2; //-2 represent access is error .wlKl[lE2
} 8A::q;
>#gDk K
K:Z(jF!j
String sHeader; =FiO{Aw`N
^j10 f$B
>pJ#b=
for(int i=1;;i++) ;kR=vv
{ 3J/l>1[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )iK:BL*Nw
//Utility.log(in.readLine()); s5Wb iOF
sHeader=httpConnection.getHeaderFieldKey(i); zKaj<Og
if(sHeader!=null) bC) <K/Q9
{ N>Uxq&)!
if(sHeader.equals("Content-Length")) |;d#k+/;
{ 4gVIuF*pS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4vvQ7e7
break; iE_[]Vgc
} ma<uXq
} 6R$Yh0%
else c6h+8QS
break; ;+#Nb/M
} ]$sb<o .a
} rKT.~ZP\
catch(IOException e){e.printStackTrace ();} ">20`Mj8
catch(Exception e){e.printStackTrace ();} _%\%
6-g>(g
A;&YPHB
Utility.log(nFileLength); /EegP@[
_Y}cK|3
)~ &gBX
return nFileLength; ?2\oi*$
} Qgv g*KX
D/;[x{;E
YTTij|(
//保存下载信息（文件指针位置） G-R83Orl
private void write_nPos() bu $u@:q 6
{ <r>Sj/w<D
try{ WiQVZ{
output = new DataOutputStream(new FileOutputStream(tmpFile)); \i}-Y[Dg
output.writeInt(nStartPos.length); Aho*E9VW
for(int i=0;i<nStartPos.length;i++) \DBEs02
{ L<B)BEE.
// output.writeLong(nPos); ^Pu:&:ki
output.writeLong(fileSplitterFetch.nStartPos); $d4&H/u^
output.writeLong(fileSplitterFetch.nEndPos); ,`k6@4
} /(u? k%Q
output.close(); =K|#5p`
} ]l+<-
catch(IOException e){e.printStackTrace ();} n\<7`,
catch(Exception e){e.printStackTrace ();} @$;8k }
} =VT\$ 5A
;_|4c7
6U$e;cr6
//读取保存的下载信息（文件指针位置） \Y8 sIs
private void read_nPos() 7sWe32
{ |-S+x]9
try{ "O|.e`C%^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); | WTWj
int nCount = input.readInt(); :=5X)10
nStartPos = new long[nCount]; _'X
nEndPos = new long[nCount]; !y>up+cRjl
for(int i=0;i<nStartPos.length;i++) 4i}nk T
{ q4G$I?4
nStartPos = input.readLong(); XZ3fWcw[
nEndPos = input.readLong(); W,H=K##6<
} 'Nuy/\[{\
input.close(); P{:Zxli0
} 2mMi=pv9
catch(IOException e){e.printStackTrace ();} ,=c(P9}^
catch(Exception e){e.printStackTrace ();} 1CSGG'J]E
} ]\oT({$6B
1;i|GXY:h
G-K{
private void processErrorCode(int nErrorCode) ^;9l3P{
{ ur=:Ha
System.err.println("Error Code : " + nErrorCode); mW+5I-~
} XzqB=iX
YktZXc?iI<
UIg?3J}R
//停止文件下载 KsK]y,^Z
public void siteStop() bmi",UZ:F
{ yHlQKI
bStop = true; 11Qi _T\
for(int i=0;i<nStartPos.length;i++) pzUr9
fileSplitterFetch.splitterStop(); ~ qaT jSP
*tk=DsRW
.O(9\3q\
} >j$aY
} i_*.
//负责部分文件的抓取 RP[`\
**FileSplitterFetch.java 9^`cVjD5
*/ &,:!gYN
package NetFox; *//z$la
2Oyw#1tdn
["Tro;K#
import java.io.*; #CAZ}];Qx
import java.net.*; _*8 6
}u$c*}
dTu*%S1Z
public class FileSplitterFetch extends Thread { JKO*bbj
n9k
Nh/i'q/
String sURL; //File URL OI78wG
long nStartPos; //File Snippet Start Position j!oX\Y-:&
long nEndPos; //File Snippet End Position /FpPf[
int nThreadID; //Thread's ID m\/)m]wR
boolean bDownOver = false; //Downing is over ZWzr8oY)
boolean bStop = false; //Stop identical yV(9@lj3;
FileAccessI fileAccessI = null; //File Access interface -"a(<JC^NI
+ZiYl[_|
"^BA5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m_Z(osoE#W
{ h&v].l
this.sURL = sURL; XeY[;}9
this.nStartPos = nStart; {D|ST2:E
this.nEndPos = nEnd; ;lrO?sm
nThreadID = id; CR2.kuM0~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G %\/[ B
} H\E%.QIx
?"<m{,yQI
*zDDi(@vtK
public void run() M5dEZ
{ -MsL>F.]
while(nStartPos < nEndPos && !bStop) Qt_KUtD
{ ad47 42
Tz.okCo]z
qwnVtD
try{ J kAd3ls
URL url = new URL(sURL); 9^N(s7s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c=bK_Z_
httpConnection.setRequestProperty("User-Agent","NetFox"); Hg8 4\fA
String sProperty = "bytes="+nStartPos+"-"; <RbfW'<G
httpConnection.setRequestProperty("RANGE",sProperty); V?)V2>]
Utility.log(sProperty); w9RBT(u
C?]eFKS."
MZcvr9y
InputStream input = httpConnection.getInputStream(); _s5FYb#
//logResponseHead(httpConnection); D)l\zs%ie
vlZmmQeJm
#Dz"g_d
byte[] b = new byte[1024]; p1i}fGS
int nRead; Vkd_&z7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KLVYWZib
{ x%goyXK
nStartPos += fileAccessI.write(b,0,nRead); k$8Zg*)
//if(nThreadID == 1) NG:4Q.G1g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :sLg$OF
} (JnEso-V
+j+ v(-
K3h7gY|.
Utility.log("Thread " + nThreadID + " is over!"); _/cX!/"
bDownOver = true; QlR~rFs9t
//nPos = fileAccessI.write (b,0,nRead); j%Z5[{!/,X
} C2=PGq
catch(Exception e){e.printStackTrace ();} iQG]v[$
} matm>3n
} 4x4[
O{7#Xj :_
3vAP&i'I
//打印回应的头信息 <gH-`3J6
public void logResponseHead(HttpURLConnection con) 0pW;H|h
{ ]GCw3r(!
for(int i=1;;i++) 1|ddG010
{ ot!m=s
String header=con.getHeaderFieldKey(i); &(Hw:W9
if(header!=null) G?\eO&QG{"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ex*{iJ;\
Utility.log(header+" : "+con.getHeaderField(header)); {}iS5[H]
else u8|CeA
break; I?%q`GyP5
} Qy4Pw\
} !v9`oL26
'/9MN;_
wxj}k7_(`A
public void splitterStop() QfPw50N;
{ g+QIhur
bStop = true; `_ M+=*}
} 4oryTckS
Iw( wT_
Knb(MI6
} 1{d;Ngx
(f_J @n
T<Qa`|5>
/* B~qo^ppVU
**FileAccess.java c'Ibgfx%m
*//文件访问(定位，写) oAB:H\
package NetFox; `nEqw/I
import java.io.*; f O+lD
?Ov~\[) F
n6Uf>5
public class FileAccessI implements Serializable{ < ]+Mdy
wmXI8'~F&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z-g6d(
RandomAccessFile oSavedFile; ;1nXJ{jKw
long nPos; Y9vi&G?Jl
gae=+@z
5T(cy
public FileAccessI() throws IOException 7,Z<PE
{ ZHeq)5C ;f
this("",0); 6|3 X*Orn
} NRT]dYf"z
Xppb|$qp4H
nec}grA
public FileAccessI(String sName,long nPos) throws IOException QOrMz`OA
{ 3b_/QT5!
oSavedFile = new RandomAccessFile(sName,"rw"); 0CXXCa7!
this.nPos = nPos; `r3 klL,W'
oSavedFile.seek(nPos); bXXX-Xc
} gYk5}E-
;YMg4Cs
R;A8y
public synchronized int write(byte[] b,int nStart,int nLen) ?P>4H0@I+
{ u#^l9/tl
int n = -1; iPWr-
try{ w{*V8S3h9
oSavedFile.write(b,nStart,nLen); @o'L!5Y
n = nLen; 9h)8Mq+M
} :~srl)|)
catch(IOException e) 3ZyvX]@_
{ g`C8ouy
e.printStackTrace (); W_Hoa*~
} ~@X3qja
jJt4{c
5M5vxJ)Lh
return n; wxPl[)E
} " Qyi/r41
*f>\X[wN
Jq?zr]"A
} ,2 W=/,5A
<&#]|HGc
.q4$)8[Pg
/* 9Hb|$/FD
**SiteInfoBean.java afD {w*[8
*/ ?K2}<H-
package NetFox; cTRtMk%^
QUvSeNSp
E.ji;5
public class SiteInfoBean { &N6[*7
/]-yZ0hX0O
:Mh\;e
private String sSiteURL; //Site's URL /cUu]#h
private String sFilePath; //Saved File's Path +_bxza(ma{
private String sFileName; //Saved File's Name iD])E/
private int nSplitter; //Count of Splited Downloading File z#P`m,~t0
`{ HWk^
k\j_hu
public SiteInfoBean() "%a<+D
{//nSplitter的缺省值为5 W+U0Y,N6
//default value of nSplitter is 5 }gt)cOaY
this("","","",5); g"m9[R=]6
} &HAu;u@
d8+@K&z|
^ACrWk~UY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J-uQF|
{ |s(Ih_Zn
sSiteURL= sURL; l`A&LQ[
sFilePath = sPath; t?PqfVSq
sFileName = sName; ScD E)r
this.nSplitter = nSpiltter; =>evkaj
mXS]SE
XK@&$~iA3
} YX)Rs Vf
r@vt.t0#
XOI"BLd
public String getSSiteURL() )rAJ>;
{ '@M"#`#0
return sSiteURL; <-n^h~,4
} fc<y(uX
EStui>ho
(y&sUc9
public void setSSiteURL(String value) d6JW"
{ i4h`jFS
sSiteURL = value; |mRlP5
} ePJ_O~c
"M /Cl|z
JR15y3F
public String getSFilePath() kN{$-v=K
{ lz<' L. .
return sFilePath; k0ai#3iJ
} G}+@C]
eiyr^Sch.
8Yf*vp>T/x
public void setSFilePath(String value) >1Hv c7DP
{ W}3%BWn
sFilePath = value; vxC];nCC#
} zp}pS2DU
gt(p%~
d4^x,hzV
public String getSFileName() /^k%sG@?
{ YG:^gi
return sFileName; rTVv6:L
} DC1.f(cdR
Ert={"Q
8M,@Mbn
public void setSFileName(String value) An0N'yo"Z
{ Ay 4P_>^
sFileName = value; PlS)Zv3
} [M%?[E}>
*c/V('D/
)AR-b8..o
public int getNSplitter() \<T7EV.
{ FGyrDRDwC
return nSplitter; p_&B+ <z
} x7<l*WQ
\zFCph4
c*E7nc)u
public void setNSplitter(int nCount) \mJR^t
{ ~1}fL 1~5
nSplitter = nCount; j$/#2%OVN
} $t}W,?
} (}>)X]
x4wTQ$*1
wEX<[#a-
/* MaY_*[
**Utility.java 0uW)&>W
*/ UYJ>L
package NetFox; +}?%w|8||s
Al8Dw)uG{
$ ~%Y}Xt*
public class Utility { I(7iD. ^:
Q(yg bT
!^98o:"x
public Utility() uM\\(g}
{ LA59O@r
cl]W]^q-Cx
Te?PYV-
} &-Wt!X 3
8N9,HNBT$
//线程睡眠 mk!8>XvM
public static void sleep(int nSecond) w42{)S"
{ SC4jKm2
try{ RfD#/G3|
Thread.sleep(nSecond); /|UbYe,
} oPaoQbR(A
catch(Exception e) vf<Dqy<M.
{ HDzeotD
e.printStackTrace (); @}!?}QU
} {v=[~H>bt
} dnwzf=+>e
>.od(Fh{l|
//日志 4xalm
public static void log(String sMsg) W=293mME
{ ~'0n ]Fw
System.err.println(sMsg); }b}jw.2Wu
} \_R<Q?D+
R[v<mo[s
L&:A59)1k
public static void log(int sMsg) Vraz}JV
{ nFGX2|d
System.err.println(sMsg); 4 Sk@ v
} F-ofR]|)>
} 4f8XO"k7t=
@g;DA)!(
%++: K
/* UukY9n];]
**TestMethod.java noa+h<vGb
*/ r1RM7y
package NetFox; 2h*aWBLk
%P<fz1
h,BPf5\S
public class TestMethod { $t"QLsk0
+N+117m
mr#.uhd.z
public TestMethod() Fec4#}|
{ ///xx/weblogic60b2_win.exe {6qxg_{
try{ :PY8)39@K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ev [?5R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <im}R9eJ1
SiteFileFetch fileFetch = new SiteFileFetch(bean); e<`?$tZ3
fileFetch.start(); >Jn`RsuV
} lnjs{`^
catch(Exception e){e.printStackTrace ();} "10\y{`v^
KV&6v`K/N
F 8sOc&L
} $J)`Ru6.
!qlk-0&`
M3]eqxLC
public static void main(String[] args) bVN?7D(
{ _]Ob)RUVH
new TestMethod(); iS.gN&\z^
} 9yTkZ`M28
} =1|p$@L`%
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