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)); ^WB[uFt-
} ,nYa+e
for(int i=0;i<nEndPos.length-1;i++) 3R<r[3WP
{ w3,KqF
nEndPos = nStartPos[i+1]; CmBPCjh
} ^$P_B-C N
nEndPos[nEndPos.length-1] = nFileLength; :G 5p`;hGo
} K*j OrQf`
} o4p5`jOG@
hx0t!k(3
3g!Z[SZ
//启动子线程 4A@HR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wd7*7']
for(int i=0;i<nStartPos.length;i++) 8J'5%$3u
{ u;$qJjS N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B0b|+5WhR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k_}$d{X
nStartPos,nEndPos,i); $V3If
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L?nhm=D
fileSplitterFetch.start(); MXaik+2
} t#P7'9Se8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |.Vgk8oTl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v];YC6shx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8i] S[$Fc
nEndPos = " + nFileLength); (Z>?\iNJ
// fileSplitterFetch[nPos.length-1].start(); mh"PAp
o=Z:0Ukl]
*Hn=)q
//等待子线程结束 zqj|$YNC
//int count = 0; Fxa{ 9'99
//是否结束while循环 ,|RKM
boolean breakWhile = false; i}8OaX3x
(.N n|lY<i
E'{:HX
while(!bStop) @lDnD%vZ`
{ n>u_>2Ikkj
write_nPos(); 9<rs3 84
Utility.sleep(500); ]vf_4QW=
breakWhile = true; OSO MFt
m&=Dy5
Rp2h[_>
for(int i=0;i<nStartPos.length;i++) b)IQa,enH
{ 8g8eY pG
if(!fileSplitterFetch.bDownOver) %TI3Eb
{ jX4$PfOhR
breakWhile = false; ^!^M Gzu
break; -sv%A7i
} mxCneX
} *^@b0f~vj
if(breakWhile) k 76<CX
break; ?a,#p
6P@K]jy& n
cu1!WD
//count++; 8zMGpY#
//if(count>4) rEp\ld
// siteStop(); C"n!mr{srt
} O\Y*s
P'B|s/)
U~BR8]=G
System.err.println("文件下载结束！"); rYt|[Pk
} kO`!!M[Oo
catch(Exception e){e.printStackTrace ();} x_O:IK.>
} 92Gfxld\
uy2~<)
-,*m\Fe}
//获得文件长度 a=ZVKb
public long getFileSize() {w3<dfJ
{ pFd{Tdh
int nFileLength = -1; kJB:=iq/x$
try{ .7 j#F
URL url = new URL(siteInfoBean.getSSiteURL()); uDG>m7(}/h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 38-kl,Vw
httpConnection.setRequestProperty("User-Agent","NetFox"); @>VX]Qe^X
zK~_e\m
!lg_zAV
int responseCode=httpConnection.getResponseCode(); 9+*{3 t
if(responseCode>=400) Heqr1btK
{ PSAEW.L
processErrorCode(responseCode); Y/UvNb<lK
return -2; //-2 represent access is error vO?sHh
} Zt41fPQ
7>zUT0SS
[H!do$[>
String sHeader; Z~(X[Zl :
VG7#C@>Z
19R~&E's
for(int i=1;;i++) &to~#.qc
{ U7U&^s6`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1h`F*:nva
//Utility.log(in.readLine()); OSuQ7V
sHeader=httpConnection.getHeaderFieldKey(i); KgYQxEbIW
if(sHeader!=null) IX 6 jb"
{ }Uj-R3]}K
if(sHeader.equals("Content-Length")) HrLws95'
{ _~1O#*|4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jon3ywd1Y
break; EpACd8Fb
} C+!=C{@7di
} Y[b08{/
else .(p_YjIA
break; P;XA|`&
} ShtV2}s|
} d$\n@}8eZp
catch(IOException e){e.printStackTrace ();} OPUrz?p2C
catch(Exception e){e.printStackTrace ();} {gEz;:!):
l(QntP
(i{ZxWW&
Utility.log(nFileLength); qldm"Ul
PU\xFt
MsIaMW_
return nFileLength; |R91|-H
} -{A64gfFxT
}|/<!l+;$
u9q#L.Ij
//保存下载信息（文件指针位置） 6e,IjocsB
private void write_nPos() mbhh
{ |w~*p N0
try{ ,3GB9
output = new DataOutputStream(new FileOutputStream(tmpFile)); oKkDG|IE
output.writeInt(nStartPos.length); wE9z@\z]
for(int i=0;i<nStartPos.length;i++) vfDX~_N
{ Iza#v0
// output.writeLong(nPos); yHf^6|$8
output.writeLong(fileSplitterFetch.nStartPos); {J)gS
output.writeLong(fileSplitterFetch.nEndPos); m(xyEU
} Y*jkUQ
output.close(); C@XnV=J
} 4%yeEc;z
catch(IOException e){e.printStackTrace ();} B&!>& Rbx
catch(Exception e){e.printStackTrace ();} ;x|?N*
} _Nz?fJ:$@
F`gK6;zp
n|.>41bJ
//读取保存的下载信息（文件指针位置） 9O&MsTmg$
private void read_nPos() _jCu=l_
{ W`#E[g?]
try{ T.{]t6t$U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HD$r<bl
int nCount = input.readInt(); s}gdi
nStartPos = new long[nCount]; W+V &
nEndPos = new long[nCount]; -:!T@rV,d
for(int i=0;i<nStartPos.length;i++) gi_f8RP=2a
{ H%>cpwa[7
nStartPos = input.readLong(); nH?#_ 5F1
nEndPos = input.readLong(); 2jQ?-/Q8#
} }*P;kV
input.close(); d_V7w4lK
} $ JCOL
catch(IOException e){e.printStackTrace ();} DoeE=X*`k
catch(Exception e){e.printStackTrace ();} LmROG-9
} n#P?JyGm1g
5NKyF
}&Xf<6
private void processErrorCode(int nErrorCode) IQ~EL';<w
{ Hb$wawy<
System.err.println("Error Code : " + nErrorCode); J rYL8 1
} cKwmtmwB
nl-tJ.MU"
L6=5]?B=
//停止文件下载 <HW2W"Go\
public void siteStop() 8f&#WIZ
{ uF*tlaV6
bStop = true; :G<~x8]k0
for(int i=0;i<nStartPos.length;i++) gHvkr?Cg
fileSplitterFetch.splitterStop(); wD pL9q
lz#@_F|.*
Hg(nC*#/Q
} Es:oXA
} EF6"PH+J@
//负责部分文件的抓取 mFC9\
**FileSplitterFetch.java <;Td8T;
*/ ,UT :wpc^i
package NetFox; ~05(92bK
8\`otJY
*U,W4>(B
import java.io.*; cbx( L8
import java.net.*; 1[?xf4EMG
bFIv}c+;
j4D`Xq2X
public class FileSplitterFetch extends Thread { Zr!CT5C5
te3\MSv;O
y2x)<.cDP
String sURL; //File URL _cc9+o
long nStartPos; //File Snippet Start Position wqQrby<
long nEndPos; //File Snippet End Position rY=dNK]d
int nThreadID; //Thread's ID \z-OJ1[F
boolean bDownOver = false; //Downing is over R|7_iMIZ
boolean bStop = false; //Stop identical ]<o^Q[OL
FileAccessI fileAccessI = null; //File Access interface d+7Dy3i|g=
PrEfJ?
sGbk4g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _7-P8"m
{ H#I%6k*\a
this.sURL = sURL; `hl1R3nBM
this.nStartPos = nStart; Wl>$<D4mO[
this.nEndPos = nEnd; 9>L{K
nThreadID = id; 7/c9azmC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \v.YP19
} .t%`"C
^ G>/;mZ
=/^{Pn
public void run() EK^["_*A
{ u6p nO
while(nStartPos < nEndPos && !bStop) V34]5
{ EDGAaN*Q
p~t5PU*(
+JBYGYN&K
try{ b@N*W]
URL url = new URL(sURL); bdyE9t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HNL;s5gq
httpConnection.setRequestProperty("User-Agent","NetFox"); P/~kX_
String sProperty = "bytes="+nStartPos+"-"; mr#XN&e
httpConnection.setRequestProperty("RANGE",sProperty); zJtB?<
Utility.log(sProperty); ~VO?PfxZ
:eTzjW=
'ul~f$ V
InputStream input = httpConnection.getInputStream(); (L8z<id<z
//logResponseHead(httpConnection); O(44Dy@2
JclG*/Wjg4
~]lVixr9
byte[] b = new byte[1024]; P'CDV3+
int nRead; -]vPF|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p7Q %)5o
{ .R>4'#8q
nStartPos += fileAccessI.write(b,0,nRead); IgU65p
//if(nThreadID == 1) xs3t~o3y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZzV%+n7<Vx
} El`f>o+EJ
aY@st]p
lip1wR7
Utility.log("Thread " + nThreadID + " is over!"); $P%b?Y/
bDownOver = true; f^[:w1X$sM
//nPos = fileAccessI.write (b,0,nRead); 3XomnL{
} #i~2C@]
catch(Exception e){e.printStackTrace ();} hA_Y@&=W
} YF<;s^&@u
} QO%#.s
")ZsY9-P
F~_)auH
//打印回应的头信息 vT>ki0P_;
public void logResponseHead(HttpURLConnection con) 7IH^5r
{ 3[O;HS3|
for(int i=1;;i++) A#B6]j)
{ 34\:1z+s M
String header=con.getHeaderFieldKey(i); u|a+:r)*4
if(header!=null) <[mvfw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i=G.{.
Utility.log(header+" : "+con.getHeaderField(header)); qdeS*rp\
else -P>f2It
break; ;\Vi~2!8
} /_MEb42&
} cfEi]
2m/=0sb\{
'v*Y7zZ#K
public void splitterStop() BVpRkUC"
{ L=wg"$
bStop = true; hhVyz{u
} m;"i4!
MHVHEwr.{
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} K6Gri>Um
fhZD[m#D
\f7Aj>
/* 3Vj,O?(Z
**FileAccess.java On{p(|l
*//文件访问(定位，写) (X"WEp^Q{I
package NetFox; Gf{FFIe(
import java.io.*; AK*F,H9
U0kEhMIIf
^SouA[
public class FileAccessI implements Serializable{ ?!J{Mrdn
s-He
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wKq-|yf,
RandomAccessFile oSavedFile; aI6fPQe
long nPos; ['SZe0
<"" fJ`7
do:3aP'S,
public FileAccessI() throws IOException 62X;gb
{ ag$mc8-p[
this("",0); 6(`Bl$M9
} hKtc
~#b&UR
.WR+)^&zz
public FileAccessI(String sName,long nPos) throws IOException 5)MVkJ=R
{ *y;(c)_w/%
oSavedFile = new RandomAccessFile(sName,"rw"); 3d2|vQx,K
this.nPos = nPos; IwHYuOED]
oSavedFile.seek(nPos); Gn*vVZ@`x
} "c6(=FFq
6^]Y])
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public synchronized int write(byte[] b,int nStart,int nLen) K)AJx"
{ Q`dzn=
int n = -1; [CU]fU{$
try{ ]oN:MS4r
oSavedFile.write(b,nStart,nLen); 5mD]uB9
n = nLen; vbeYe2;(
} Cku&s
catch(IOException e) q>T7};5m2
{ 8yH*
e.printStackTrace (); ?vgHu
} :Z@!*F
S;vE%
Z[DiLXHL
return n; { L(Q|bB
} Q_bF^4gt
+a%Vp!y
RQZ|:SvV
} F;mK)Q-
}?pY~f
sz'IGy%
/* KMxP%dV/=
**SiteInfoBean.java "YUyM5X
*/ IQFt4{aK3
package NetFox; {o?+T);Z
6}YWM]c%
^&'&Y>
public class SiteInfoBean { )vFJx[a<n`
wj fk >
jrMY]Ea2`
private String sSiteURL; //Site's URL p=Nord
private String sFilePath; //Saved File's Path ubn`w=w$
private String sFileName; //Saved File's Name >4A~?=
private int nSplitter; //Count of Splited Downloading File ,1"w2,=
'[ZRWwhr
cC.=,n
public SiteInfoBean() LCrE1Q%VP
{//nSplitter的缺省值为5 |=7ouFl
//default value of nSplitter is 5 XCNfogl
this("","","",5); AZ7
} Nj2f?',;U
o5(p&:1M
8:%=@p>$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?qeBgkL(B^
{ JCu3,O!q
sSiteURL= sURL; zW`$T88~
sFilePath = sPath; YEZd8Y
sFileName = sName; Zc"Vf]:
this.nSplitter = nSpiltter; :wJ=t/ho
$td=h)S^`
:>U2yI
} %z6.}4h
'1lr "}"Q+
5} 9}4e
public String getSSiteURL() X]J]7\4tF\
{ 7gR8Wr ^
return sSiteURL; =(f+geA"hm
} h*_h M1*;
"5]Fl8c?
_`>F>aP
public void setSSiteURL(String value) D}SYv})Ti
{ EK^B=)q6:W
sSiteURL = value; ;- D1n
} bwjjwu&
3@ a
JJHr<|K
public String getSFilePath() sN^3bfi!i
{ &+?JY|u
return sFilePath; @(Mg>.P
} \bze-|C
r7z8ICX'q
#On EQ:
public void setSFilePath(String value) lP>}9^7I!
{ Vy-EY*r|
sFilePath = value; C3n_'O
} 2\flTO2Ny
;\@co5.=
olNgtSX
public String getSFileName() T~%}(0=m
{ HH>"J/;c,
return sFileName; cTO\Vhg
} 8Wn;U!qT
wN[mU
;2||g8'
public void setSFileName(String value) -c-#1_X5
{ Ju""i4
sFileName = value; EP.nVvuL
} =yv_i]9AN
W\s ]qsLS
GY@-}p~it
public int getNSplitter() L-}>;M$Y)
{ box(FjrZE
return nSplitter; (f DA
} E|ce[|2
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tAfdbt
public void setNSplitter(int nCount) xtef18i>
{ 1Ih.?7}
nSplitter = nCount; I\JJ7/S`t
} ;=IC.<Q<}
} $d1+d;Mn
=VMV^[&>
Oj<.3U[C
/* 8+no>%L
**Utility.java GE`:bC3
*/ ,f`435R
package NetFox; k r0PL)$
#hEN4c[Ex
W+ tI(JZ
public class Utility { vkdU6CZO
G1 ?."
+8e~jf3E1
public Utility() | ,bCYK
{ __p\`3(,'
E DuLgg@
Qe=,EXf
} k!e \O>+
N zY}-:{
//线程睡眠 I^iJ^Z]vx
public static void sleep(int nSecond) F+A"-k_\T#
{ BU[.P]
try{ BJI}gm2y
Thread.sleep(nSecond); w%=GdA=
} TrxZS_
catch(Exception e) j4wcxZYY~
{ ,?Pn-aC+
e.printStackTrace (); #J.v[bOWQ
} h^F^|WT$
} M_tY:v
Ri]7=.QI`
//日志 ~~[Sz#(
public static void log(String sMsg) 2}Dd{kC-
{ YfBb=rN2s
System.err.println(sMsg); 0-H!\IB
} _3UH"9g{
z;:c_y!f
6QsH?!bu
public static void log(int sMsg) 3L$_OXx
{ -%]O-'
System.err.println(sMsg); %(a<(3r
} a!MhxM5
} L8K=Q
5y7rY!]Bf
#3@ Du(_n
/* 2j_YHv$I
**TestMethod.java ahi lp$v
*/ 3w9j~s
package NetFox; ?bc-?<Xk
)X{x\ /N
%u\Oj \8U
public class TestMethod { *"V5j#F_
:[:5^R
6e,|HV
public TestMethod() D>9~JHB
{ ///xx/weblogic60b2_win.exe tx}}Kd
try{ J(*qOGBD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aY8"Sw|4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >jEn>H?
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xz)UH<
fileFetch.start(); 'Eds0"3
} -x~h.s,
catch(Exception e){e.printStackTrace ();} m9bR %j
&jCT-dj
* z|i{=W F
} Wx#((T
< aeBhg%
q[4{Xh
public static void main(String[] args) \F]X!#&+
{ )(~s-x^\z@
new TestMethod(); oJC-?
} OgJd^
} CW*Kdt
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