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)); B$)KZR(u
} 7{6wNc
for(int i=0;i<nEndPos.length-1;i++) grZN.zTO
{ yt?#T#
nEndPos = nStartPos[i+1]; ,W.O*vCA
} Mf?4 `LM
nEndPos[nEndPos.length-1] = nFileLength; d%WFgf}
} >6Q-e$GS@
} m#uutomi0
BJqM=<nQ
hSxf;>(d
//启动子线程 17-K~ybc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mV-MJ$3r
for(int i=0;i<nStartPos.length;i++) xMe[/7)4
{ &4DWLI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <3i!{"}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gX[6WB"p
nStartPos,nEndPos,i); y<)x`&pcD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f+rBIE
fileSplitterFetch.start(); #6JG#!W
} /gxwp:&lY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zvc{o8^z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'INdZ8j_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cEe>Lyt
nEndPos = " + nFileLength); xSw ^v6!2
// fileSplitterFetch[nPos.length-1].start(); Ax&+UxQ0|
+?%huJYK,
W)\~T:Kn
//等待子线程结束 X4jtti
//int count = 0; #U^@)g6
//是否结束while循环 X"yLo8y8$
boolean breakWhile = false; <=WQs2
)AnX[:y
lE4.O
while(!bStop) Y#KgaZ7N
{ i),W1<A1
write_nPos(); < d?O#(
Utility.sleep(500); UtzW5{
breakWhile = true; }z}oVc
v=!]t=P)t
0Nmd*r
for(int i=0;i<nStartPos.length;i++) K?) &8S
{ @X|CubJ
if(!fileSplitterFetch.bDownOver) E;k'bz
{ %|UCs8EFm
breakWhile = false; <}G7#xg
break; G"wy?
} 0Y{A
} yKi* 8N"e<
if(breakWhile) ^dQ#\uy
break; $cnIsyKWY
60Y&)UR
gz8<&*2
//count++; ;'*"(F=D6
//if(count>4) @Kp2l<P
// siteStop(); ~qs97'
} 4\>Cnc{
Q1g@FsW&U
M*|x,K=U
System.err.println("文件下载结束！"); Ue! &Vm
} 'RXhE
catch(Exception e){e.printStackTrace ();} 9|fg\C
} 5EM(3eY^q
s~,Ypo?
-|T.APxB
//获得文件长度 SO9j/
public long getFileSize() 2ACN5lyUS
{ 2]hQ56Yv3
int nFileLength = -1; ml\A)8O]j/
try{ Tmqtj
URL url = new URL(siteInfoBean.getSSiteURL()); ^As^hY^p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >HXT:0
httpConnection.setRequestProperty("User-Agent","NetFox"); VD,g
n)gzHch
k68\ _NUL
int responseCode=httpConnection.getResponseCode(); -b8Vz}Y
if(responseCode>=400) CM_FF:<tn
{ ;mu^WIj
processErrorCode(responseCode); ^ 14U]<
return -2; //-2 represent access is error o/ ozX4C
} m\RU|Z
s7[du_)
GG-7YJ
String sHeader; `;L>[\Xi
JdF;*`_7*
Y:XE4v/)@L
for(int i=1;;i++) 1ve %xF
{ D:4Iex9$F"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); unKi)v1
//Utility.log(in.readLine()); nDhr;/"i
sHeader=httpConnection.getHeaderFieldKey(i); NJRk##Z
if(sHeader!=null) _SY4Qs`d
{ +iY.YV
if(sHeader.equals("Content-Length")) R.-2shOE'
{ Kf/1;:^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fYBmW')
break; 07`hQn)Gc
} 8>%:MS"
} $hXhq*5|c
else W1fEUVj
break; @@M 2s(
} JHC 6l
} 7.`Fe g.
catch(IOException e){e.printStackTrace ();} ]3nka$wA*
catch(Exception e){e.printStackTrace ();} .5Sw
`7[z%cuK
yY+)IU.
Utility.log(nFileLength); |uf{:U)
xM"k qRZ
>)\x\e
return nFileLength; m^I+>Bp/:
} ZCVwQ#Xe+
)RG@D\t,
%5Q5xw]w3
//保存下载信息（文件指针位置） p=sLKnLmZ
private void write_nPos() GgwO>[T
{ Sc#B-4m
try{ =:Ahg 9
output = new DataOutputStream(new FileOutputStream(tmpFile)); OeLM*Zi
output.writeInt(nStartPos.length); d^p af
for(int i=0;i<nStartPos.length;i++) o."k7fLB
{ 845a%A$
// output.writeLong(nPos); kV9S+ME
output.writeLong(fileSplitterFetch.nStartPos); :p%G+q2
output.writeLong(fileSplitterFetch.nEndPos); 2O;Lw@W
} 8`~M$5!
output.close(); uyZ
} P@lDhzd
catch(IOException e){e.printStackTrace ();} O|wu;1pQ
catch(Exception e){e.printStackTrace ();} )IQ5Qu
} bS7rG$n [
>ka*-8?
~QzUQYG*
//读取保存的下载信息（文件指针位置） qRi;[`
private void read_nPos() jd ]$U_U(
{ P5-1z&9O
try{ 0se0AcrW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ts|dk%
int nCount = input.readInt(); A8tzIh8
nStartPos = new long[nCount]; YD>5zV%!D
nEndPos = new long[nCount]; 3h N?l :/b
for(int i=0;i<nStartPos.length;i++) Zcst$Aro
{ :buH\LB*P
nStartPos = input.readLong(); 17kh6(X
nEndPos = input.readLong(); KT'Ebb]
} K=lm9K
input.close(); PY.4J4nn|
} IY_u|7d
catch(IOException e){e.printStackTrace ();} ^K[WFiN}
catch(Exception e){e.printStackTrace ();} k+qxx5{
} v_=xN^R
}#'I,?_k
f0"N
private void processErrorCode(int nErrorCode) LelCjC{`1
{ ;6+e!h'1
System.err.println("Error Code : " + nErrorCode); =T7lv%u
} P}kBqMM
5@c/,6l
(h&XtFul}
//停止文件下载 #WE"nh9f|z
public void siteStop() <7
{ ct o+W}k
bStop = true; 3QM;K^$
for(int i=0;i<nStartPos.length;i++) w2 %u;D%
fileSplitterFetch.splitterStop(); fyHFfPEE
}enS'Fpf`
/w[B,_ZKTk
} o}^/Km+t
} @bfW-\ I
//负责部分文件的抓取 R{6~7<m.
**FileSplitterFetch.java Ei$?]~ &
*/ ppYIVI
package NetFox; \Dn47V{7-
Q5K<ECoPk
`3wzOMgJ
import java.io.*; t?&@bs5~g
import java.net.*; *,x-}%X
d;:H#F+ (
MawWgd*
public class FileSplitterFetch extends Thread { XHN*'@ 77;
J)kH$!csi
8)KA {gN}
String sURL; //File URL Nj5V" c
long nStartPos; //File Snippet Start Position 0XgJCvMcB
long nEndPos; //File Snippet End Position +O]jklS4H
int nThreadID; //Thread's ID J~jxmh
boolean bDownOver = false; //Downing is over 322)r$!"
boolean bStop = false; //Stop identical N"',
FileAccessI fileAccessI = null; //File Access interface 1&7~.S;km
-=;V*;
uDe%M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException . W7ZpV
{ fCMFPhF
this.sURL = sURL; U<|hIv-&
this.nStartPos = nStart; KzgW+6*G
this.nEndPos = nEnd; bh Nqj
nThreadID = id; f52*s#4}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h=a-~= 8
} 9>QGsf.3
Gl!fT1zh0
l^~E+F~
public void run() \jR('5DcB
{ }Cs.Hm0P
while(nStartPos < nEndPos && !bStop) r}>q*yx:
{ ~k(4eRq
3AQu\4+A
Q|$?d4La8
try{ t%k1=Ow5i
URL url = new URL(sURL); %@q/OVnM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 31cC*
httpConnection.setRequestProperty("User-Agent","NetFox"); %)t9b@c!}
String sProperty = "bytes="+nStartPos+"-"; J 7/)XS
httpConnection.setRequestProperty("RANGE",sProperty); NT1"?Thx|
Utility.log(sProperty); isF jJPe
g %ZKn
bjq+x:>
InputStream input = httpConnection.getInputStream(); \h{M\bSIEa
//logResponseHead(httpConnection); U@'F9UB`
3oo Tn-`{
f+c<|"we
byte[] b = new byte[1024]; Le?yzf
int nRead; SWq5=h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s.uw,x
{ dv7IHUFf
nStartPos += fileAccessI.write(b,0,nRead); l<DpcLX
//if(nThreadID == 1) H?H(=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bP+b~!3
} ;$FpxurX
hQFF%xl
?|$IZ9
Utility.log("Thread " + nThreadID + " is over!"); `i"7; _HoV
bDownOver = true; ^q@6((O
//nPos = fileAccessI.write (b,0,nRead); bMCy=5
} ^Gt9.
catch(Exception e){e.printStackTrace ();} 3;E,B7,mQ
} fGf C[DuY
} \9Yc2$dY
GEd JB=
^#0k\f>_
//打印回应的头信息 h%=>iQ%enc
public void logResponseHead(HttpURLConnection con) Shag4-*@hi
{ BKJwM'~
for(int i=1;;i++) J]"IT*-Ht
{ Cju%CE3a
String header=con.getHeaderFieldKey(i); Jx-dWfe
if(header!=null) ",Ge:\TR=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); USrBi[_ci\
Utility.log(header+" : "+con.getHeaderField(header)); l,w$!FnmR
else 9$iDK$%
break; Vmb `%k20'
} p$+.]
} naaww
IPTEOA<M[
q\I2lZ
public void splitterStop() 9FKowF_8
{ PKK18E}{%^
bStop = true; jn:9Cr,o;g
} qiyX{J7Z
OtsW>L@ O(
}$wWX}@
} ==^9_a^
[m+):q^
QKAt%"1&
/* ?*K{1Ghf
**FileAccess.java W&'[Xj
*//文件访问(定位，写) Up*.z\|'y
package NetFox; MmL)CT
import java.io.*; z{uRqAG
YB?5s`vr9d
v "Yo
public class FileAccessI implements Serializable{ id=:J7!QU
+m+v1(@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (imaL,M-D
RandomAccessFile oSavedFile; m,1Hlp
long nPos; W6y-~
'U|Tye i?
O&vE 5%x
public FileAccessI() throws IOException R>#BJ^>=
{ '^#=,+ A
this("",0); V!XT=Ou?6
} fa:V8xa
qHtonJc
x<lY&KQ0
public FileAccessI(String sName,long nPos) throws IOException XqxmvN
{ [>#@?@x`P
oSavedFile = new RandomAccessFile(sName,"rw"); l+!eC lM%
this.nPos = nPos; fk)5TPc^
oSavedFile.seek(nPos); EW}7T3g
} tOEY|
)B1gX>J\8
or)v:4PXW
public synchronized int write(byte[] b,int nStart,int nLen) s/cclFji]
{ Rg,]du u?
int n = -1; Q}qw`L1
try{ ;+6TZqklQ
oSavedFile.write(b,nStart,nLen); k&M9Hn2
n = nLen; g)/#gyT4Y
} >$ok3-tuU
catch(IOException e) vk>EFm8l
{ QswbIP/>:'
e.printStackTrace (); eX0ASI9
} 8-.jf
F&[MyXU4
Mb +
return n; M>m+VsJV
} |Js?@
x4 .Y&Wq#
C#3K.0a
} <JkmJ/X
8-clL\bm
Qi?xx')
/* )o\U4t
**SiteInfoBean.java J\fu6Ti
*/ z!> H^v
package NetFox; AhauNS^"{R
_ giZ'&l!
Rk(2|I
public class SiteInfoBean { y%NZ(Y,v
bxFDB^
{DVu* %|
private String sSiteURL; //Site's URL oD?c]}3
private String sFilePath; //Saved File's Path Vh o3I[C
private String sFileName; //Saved File's Name :0o,pndU
private int nSplitter; //Count of Splited Downloading File DwBKqhu
ZBcT@hxm
\Ng|bWR>LQ
public SiteInfoBean() XaH%i~}3
{//nSplitter的缺省值为5 ;c;5O@R}3
//default value of nSplitter is 5 rV6SN.
this("","","",5); ZlEH3-Zv
} \&#pJBBG
SIr^\iiOB
klON6<w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VzZ'W[/7)B
{ sn=_-uoU
sSiteURL= sURL; HAOl&\)7"_
sFilePath = sPath; ~4{|
sFileName = sName; ^9wQl!e ob
this.nSplitter = nSpiltter; #G`UR
W:V:Ej7 h
;wF 0s
} <~ 9a3c?
_Vl22'wl
b0n " J`
public String getSSiteURL() Cg4l*"_
{ OqNtTk+
return sSiteURL; ^;[|,:8f7L
} 64jFbbd-/
fO'"UI
#eKg!]4-R
public void setSSiteURL(String value) `L#`WC@[o
{ FvTc{"w /
sSiteURL = value; 20Rj Rd
} QW[ gDc
X6`F<H`
\u@*FTS
public String getSFilePath() /6@~XO)w
{ .{}=!>U2
return sFilePath; (|kcSnF0
} @UgZZ
|MEu"pY)
I(2qXOG
public void setSFilePath(String value) |?=a84n1l
{ +^0Q~>=VD
sFilePath = value; IA$)E
} `$hna{e^n
d=J$H<
S(nZ]QEG
public String getSFileName() ,KO_h{mI<
{ 5OS|Vp||b
return sFileName; q5D_bm7,3
} F4T}HY>nZ
ja1WI
F[HMX4
public void setSFileName(String value) dd=';%?
{ [@RJ2q$
sFileName = value; ]u\K}n6[q
} )4@La&
=:~%$5[[
p(J,fus
public int getNSplitter() ud}B#{6
{ a9<&|L <
return nSplitter; b{WEux{)
} |#x]FNg
h%0hryGB
`EjPy>kM
public void setNSplitter(int nCount) }%m:^*@$9
{ iR`c/
nSplitter = nCount; N9s ,..
} _t+.I9kQ
} Ev'BmDk
EoOB0zo}Y+
dDeImSeV
/* iCK p"(kf
**Utility.java 2:>|zmh_
*/ hrt]Qn&
package NetFox; .JG>/+
n,.ZLuBEX
<l,Kg 'v
public class Utility { hj8S#
%%=PpKYtSD
uk\-"dS
public Utility() R"0fZENTG
{ q_sQC5:s
T9,T'y>BD
w&F/P]1
} 6)QJms
VXpbmg!{S
//线程睡眠 qit D{;
public static void sleep(int nSecond) q!5 *)nw"
{ >We:gKxr
try{ GOx+%`.R\
Thread.sleep(nSecond); 3Xun>ZQ-
} q')MKR*
catch(Exception e) 3e<FlH{
{ L;n2,b
e.printStackTrace (); J:{$\m'
} D`t }V
} 2!Mwui;%
P[.BK
//日志 |kUxTe
public static void log(String sMsg) d]v4`nc
{ N<xf=a+j
System.err.println(sMsg); o9l =Q
} !+E|{Zj
~}c`r4
2(, `9
public static void log(int sMsg) kg>Ymo.
{ | Q Y_ci
System.err.println(sMsg); 3Mnm2*\
} \Lz2"JI
} >UP{=`
B"-gK20vY
:uAW
/* s[V$fvW
**TestMethod.java <By6%<JTn
*/ p8>.Q/4
package NetFox; ?D].Za^km
Pgy&/-u
MZ(TST"
public class TestMethod { q+MV@8w
M>mk=-l
v}=3
public TestMethod() reyN5n~4U
{ ///xx/weblogic60b2_win.exe {\OIowa
try{ @$5GxIw<l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e$k]z HlQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `Z3Qx~fx
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0L34)W
fileFetch.start(); hrwQh2sm
} YU89m7cc'
catch(Exception e){e.printStackTrace ();} {[~ !6&2(k
6,"fH{Bd
^lqcF.
} }`oe<|
[TZlvX(E
Xwg|fr+p
public static void main(String[] args) FkdG@7Xf
{ @quNVx(y
new TestMethod(); 58H[sM4>
} w1J&c'-
} wff&ci28
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