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)); _X;,,VEV!
} ZeU){CB
for(int i=0;i<nEndPos.length-1;i++) wCR! bZ w
{ ecoI-@CAI
nEndPos = nStartPos[i+1]; 8sc2r
} i$@xb_
nEndPos[nEndPos.length-1] = nFileLength; jl(D;JnF
} E QU@';~8
} fDplYn#
*ls6k`ymL
x>TIx[x
//启动子线程 }5(_gYr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Cb? !+U
for(int i=0;i<nStartPos.length;i++) h9<PP2.(
{ X1a~l|$h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CrL9|78
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '/9j"mIA9$
nStartPos,nEndPos,i); U:n~S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CLVT5pj='
fileSplitterFetch.start(); _|0#
} &dmIv[LU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :.]EM*p?GV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %7aJSuQN%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *GBV[D[G,
nEndPos = " + nFileLength); Q[K$f%>
// fileSplitterFetch[nPos.length-1].start(); oST)E5X;7
i7r)9^y
@-\=`#C**
//等待子线程结束 xZ;eV76
//int count = 0; <Z3C&BM
//是否结束while循环 ~K3Lbd| r
boolean breakWhile = false; {nUmlP=mS
^\Q,ACkZb
xt pY*
while(!bStop) 1v.#ndk
{ YtSYe%
write_nPos(); 2\k!DF
Utility.sleep(500); \y=28KKc:c
breakWhile = true; l9=Ka{$^*
;w"h n*
bO/r1W
for(int i=0;i<nStartPos.length;i++) (:`4*xK
{ JU^Y27
if(!fileSplitterFetch.bDownOver) nA(" cD[,
{ qp6'n&^&
breakWhile = false; H%U
break; t`|Rn9-
} H+Bon=$cE!
} =5B5
if(breakWhile) [#Gu?L_W
break; *K$a;2WjzG
qg`ae
Zn r4^i&(
//count++; $poIWJMc
//if(count>4) ciml:"nQ
// siteStop(); wdBBx\FP
} 2ns,q0I A
BV>9U5
l:eC+[_;>
System.err.println("文件下载结束！"); ~zac.:a8
} i*mU<:t
catch(Exception e){e.printStackTrace ();} _[-MyUs
} ),B/NZ/-
hOZTD0
Ezew@*(
//获得文件长度 >"<s7$g
public long getFileSize() w/(T
{ (n?f016*%d
int nFileLength = -1; !9$}1_,is
try{ db_?da;!`
URL url = new URL(siteInfoBean.getSSiteURL()); R0*P,~L;|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U9b[t
httpConnection.setRequestProperty("User-Agent","NetFox"); @^YXE,
cRr3!<EZ
;r"r1'a+@
int responseCode=httpConnection.getResponseCode(); %gFIu.c
if(responseCode>=400) l6w\E=K
{ e#h&Xa
processErrorCode(responseCode); P(7el
return -2; //-2 represent access is error Qfy_@w]
} z,m3U(
_oBx:G6E
Y96<c" t
String sHeader; eF{uWus
v+Y^mV`|
AU`z.Isf
for(int i=1;;i++) E8sM`2z5
{ af>i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L,#YP#O,j
//Utility.log(in.readLine()); rqN+0CT
sHeader=httpConnection.getHeaderFieldKey(i); |z_Dw$-xm
if(sHeader!=null) AhOBbss]q
{ v}t{*P
if(sHeader.equals("Content-Length")) 4+d(d
{ t6KKfb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6-"tQ,AZ
break; ;k#_/c
} RbxQTM_:M
} e> 9X
else 7lwI]/ZH*
break; ti9e(Jt!O
} Sft vN-
} |-\anby<
catch(IOException e){e.printStackTrace ();} DPW^OgL;
catch(Exception e){e.printStackTrace ();} Lc}hjK
W9c&"T9JT
,D`jlY-1l
Utility.log(nFileLength); 6<S-o|Xw
R||$Rfe
M61Nl)|mx&
return nFileLength; wj}LVyV
} oP56f"BE(
!L9|iC:8
^vG<Ma.yk
//保存下载信息（文件指针位置） C7m/<
private void write_nPos() v ,h"u
{ JP\jhkn
try{ =d5;F`m
output = new DataOutputStream(new FileOutputStream(tmpFile)); >T[Y>]
output.writeInt(nStartPos.length); `fEzE\\!*
for(int i=0;i<nStartPos.length;i++) [|*7"Q(
{ u?SwGXi~8
// output.writeLong(nPos); zJ8T.+qJ
output.writeLong(fileSplitterFetch.nStartPos); dT7fyn
output.writeLong(fileSplitterFetch.nEndPos); Wkk(6gS,
} 3)=ix. wW
output.close(); HX| p4-L
} I(BJ1 8F$
catch(IOException e){e.printStackTrace ();} wY\,b*x
catch(Exception e){e.printStackTrace ();} dI7rx+L
} lbovwj
r>bgCQ#-n
O!dS;p-F
//读取保存的下载信息（文件指针位置） }+/Vk
private void read_nPos() }eZ\~2
{ Jg'#IM
try{ 6 .?0 {2s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PuZzl%i P3
int nCount = input.readInt(); b+whZtNk7
nStartPos = new long[nCount]; Z7y%
nEndPos = new long[nCount]; ,Q Ge=Exn
for(int i=0;i<nStartPos.length;i++) Kg<~Uf=1
{ R7z @y o
nStartPos = input.readLong(); N6_1iIM
nEndPos = input.readLong(); SFuSM/Pf
} Ei]SksV>*
input.close(); bg0ix"
} Q-R?y+| x
catch(IOException e){e.printStackTrace ();} Oz(=%oS
catch(Exception e){e.printStackTrace ();} m!<FlEkN
} X~o;jJC
'NjeF&#6
&DYC3*)Jih
private void processErrorCode(int nErrorCode) ~0-)S@
{ pl,XS6mB
System.err.println("Error Code : " + nErrorCode); j&S.k
} @Q ~;@M
yG~Vvpv
X[<#B5
//停止文件下载 J#@+1 Nt
public void siteStop() 8#A4B2
{ \A\?7#9\
bStop = true; 2,I]H'}^
for(int i=0;i<nStartPos.length;i++) GK11fZpO:i
fileSplitterFetch.splitterStop(); s-SFu
Z)(#D($-
ea$. +
} sEw ?349Bz
} B!)9 >
//负责部分文件的抓取 X5+^b({
**FileSplitterFetch.java mhU=^/X
*/ xp3^,x;\X
package NetFox; qPDRB.K|}
Xs$a^zZ
5'{QMnfB
import java.io.*; ^e]O >CJ
import java.net.*; #>~A-k)
w-km qh
^zqQ8{oV
public class FileSplitterFetch extends Thread { c(8>oeKyD
k:j?8o3
`]19}GK~xo
String sURL; //File URL HtE^7i*_
long nStartPos; //File Snippet Start Position 438r]f?0|{
long nEndPos; //File Snippet End Position DrBkR`a?
int nThreadID; //Thread's ID l&W:t9o
boolean bDownOver = false; //Downing is over A -8]4p::
boolean bStop = false; //Stop identical r_bG+iw7p
FileAccessI fileAccessI = null; //File Access interface 7bGt'gvv
r0&LjH&R
(C`nBiL<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %t9Kc9u3p
{ +",`Mb
this.sURL = sURL; 16z WmJH
this.nStartPos = nStart; v=dN$B5y3
this.nEndPos = nEnd; q:jv9eL.O
nThreadID = id; @sd{V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ei<+{P(t0
} _m a;b<I/<
gLo&~|=L-
=7:}/&
public void run() hlc g[Qdo*
{ %Y|AXxR
while(nStartPos < nEndPos && !bStop) ~% ]V,-4
{ u0[O /G
b=WkRj
e2nZwPH
try{ ? )IH#kL
URL url = new URL(sURL); |D'!.$7%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F$:mGyl5_
httpConnection.setRequestProperty("User-Agent","NetFox"); Q3t%JP>;g
String sProperty = "bytes="+nStartPos+"-"; =q"0GUei3
httpConnection.setRequestProperty("RANGE",sProperty); }+[!h=Bx
Utility.log(sProperty); ?"}U?m=
0,__{?!
slr>6o%W`
InputStream input = httpConnection.getInputStream(); 0}kvuuR
//logResponseHead(httpConnection); 3_eg'EP.E
P6v@ Sn
/<O9^hA|
byte[] b = new byte[1024]; %>O}bdSf
int nRead; Xpkj44cd@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [>j.x2=
{ bgInIe
nStartPos += fileAccessI.write(b,0,nRead); Ia^/^>
//if(nThreadID == 1) )J[Ady^5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .'-t>(}v
} [a^<2V!vMn
[c=![*}/
b4ke'gx
Utility.log("Thread " + nThreadID + " is over!"); P=9sP:[f6
bDownOver = true; ;gRPTk$X3
//nPos = fileAccessI.write (b,0,nRead); >u .u#de
} #fyY37-
catch(Exception e){e.printStackTrace ();} pFo,@M
} $K|2k7
} `\BBdQ#bH
{+9t!'
"JYWsE
//打印回应的头信息 :c[T@[
public void logResponseHead(HttpURLConnection con) ')fIa2dO/
{ dsK^-e6:5
for(int i=1;;i++) pG/g
{ O=1#KNS
String header=con.getHeaderFieldKey(i); D9r;Ys%
if(header!=null) ^#7&R"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q| *nd!y'
Utility.log(header+" : "+con.getHeaderField(header)); ]zvOM^l~
else T?-K}PUcQ
break; ; Oz p
} fX&g. fH
} Hu!<GB~
B=%YD"FAv
Q6[h;lzGV
public void splitterStop() _9/Af1X
{ <g8{LG0
bStop = true; <S@2%%W
} ;/^O7KM-
j8t_-sU9 i
D6FG$SV
} kN vNV(4
v[m1R'
*b1NVN$
/* B8V85R
**FileAccess.java 6y@o[=m
*//文件访问(定位，写) DsiyN:o'+
package NetFox; q1%xk=8
import java.io.*; Sa6YqOel@
"9H#pj -
D4+OWbf6
public class FileAccessI implements Serializable{ xkz`is77Y@
X*:)]p(R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c5HW.3"
RandomAccessFile oSavedFile; jATN):8W
long nPos; 4+0:(=>[%
B|BJkY'
W4AFa>h
public FileAccessI() throws IOException G9> 0w)r
{ 5kj=Y]9\I
this("",0); {E>(%vD
} ;cWFh4_
p:|p?
rAQ3x0
public FileAccessI(String sName,long nPos) throws IOException ^eqq|(<K
{ #!M;4~Sfx
oSavedFile = new RandomAccessFile(sName,"rw"); HG})VPBa
this.nPos = nPos; _d3/="=
oSavedFile.seek(nPos); Ml,87fo
} Gh{vExH@5(
2`h
X57\sggK
public synchronized int write(byte[] b,int nStart,int nLen) ^(yU)k3pu
{ mv9@Az9
int n = -1; Q<Th*t
try{ {UEZ:a
oSavedFile.write(b,nStart,nLen); 0-A@X>6bs
n = nLen; ;KW}F|
} Z<tJ+
catch(IOException e) e_CgZ
{ y+a]?`2
e.printStackTrace (); EWoGdH|
} KZTT2KsYl
SNf*2~uq)
z4c{W~}`
return n; nrI-F,1
} vC!}%sxVw_
cH\.-5NQ
|=4imM7
} `Jon^&^;|
2UjQ!g`
0N*~"j;r#M
/* Yf,U2A\
**SiteInfoBean.java /=ro$@
*/ 9mH/xP:y
package NetFox; \P0>TWE
M&K'5G)7
PaYsn *{})
public class SiteInfoBean { 5J8U] :Y)
WMd5Y`y
?i7}d@636
private String sSiteURL; //Site's URL YXhxzH hPd
private String sFilePath; //Saved File's Path `G^MTDp?L+
private String sFileName; //Saved File's Name 8;]U:tv
private int nSplitter; //Count of Splited Downloading File p_2-(n@
3)+}2
(y!<^Q
public SiteInfoBean() ue{0X\[P<
{//nSplitter的缺省值为5 r%~/y
//default value of nSplitter is 5 Kr|9??`0E
this("","","",5); Zb=H\#T
} pElAY3
OfGMeN6
z>X<Di&x)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BliL1"".
{ Qyoly"b@
sSiteURL= sURL; =E''$b?Em
sFilePath = sPath; aI:G(C?jm
sFileName = sName; zQQ=8#]
this.nSplitter = nSpiltter; p$ %D
ACcxQK}
V/}g'_E
} z<c@<M=Q*
ZkZTCb`/l
48 `k"Uy
public String getSSiteURL() 6{p]cr
{ c31k%/.
return sSiteURL; (},TZ+u
} X!%CYmIRb
4:p+C-gs
3jB5F0^r1
public void setSSiteURL(String value) 2'zYrdem
{ +5:oW~ ;
sSiteURL = value; yY$:zc"J
} yH0BNz8V
3-5X^!C
-_RMiGM?T
public String getSFilePath() Oy^)lF/
{ ,f;YJHEx8
return sFilePath; :Ojsj_Z;;
} ~]_gq;bG
d)&}% 2ku
Z&!5'_9{V
public void setSFilePath(String value) S-\;f jh
{ ')Drv)L
sFilePath = value; rmOcA
} 5[_|+
'%$)"g]/#
CG(G){u&
public String getSFileName() bZ.q?Hlfk
{ P<@V
return sFileName; e-dpk^-
} t_PAXj
"[ 091<
D/1f>sl
public void setSFileName(String value) ,s*-2Sz
{ WZa?Xb
sFileName = value; &cEQ6('H
} wua`e <"
dd +%d
1 U|IN=
public int getNSplitter() k%5o5Hx
{ O.%' 47A
return nSplitter; '<.@a"DnJ
} $-zt,iRyV
H53dy*wb$
GoK[tjb
public void setNSplitter(int nCount) ]YP J.[n
{ O|opNr
nSplitter = nCount; M7|k"izv
} i1"4ztZ
} Yz?4eSa/
4PwjG;!K
$y\\?
/* ^x8yWbrE
**Utility.java )c:i'L
*/ y Q_lJIX
package NetFox; -^i[
IXaF(2>
MY]Z@
public class Utility { a&3pPfC
dVh* a
h7iI=[_V
public Utility() %. =B=*
{ Gm0&y
'+6SkZ
p_x@FA(
} nwOT%@nw
Lc<v4Bp
//线程睡眠 ~|_s2T
public static void sleep(int nSecond) U8+5{,$\.
{ qHT_,\l2
try{ Q:6i 3 Nr/
Thread.sleep(nSecond); aXAV`%b
} 'rZYl Qm
catch(Exception e) Cy'0O>v5
{ 3]=j!_yJf
e.printStackTrace (); \^$g%a
} Fc{X$hh<
} vN`2KCl~3
\G+ hi9T(
//日志 FwB}@)3
public static void log(String sMsg) <6_RWtU
{ ^XsIQz[q
System.err.println(sMsg); TC7Rw}jF
} j:)"s_
[YbnpI
|~'PEY
public static void log(int sMsg) hmfO\gc}y
{ 5C}1iZEJ
System.err.println(sMsg); ~(( '1+
} ){u/v[O9"
} +j*hbG=
KCE5Z?k
O$=[m9V
/* i(hI\hD
**TestMethod.java k E^%w?C
*/ ;}iV`)S
package NetFox; p~/
;7jszs.6%
}Zs y&K
public class TestMethod { '<}N`PS#N
6FYO5=R
~]CQ DR:
public TestMethod() |\PI"rW
{ ///xx/weblogic60b2_win.exe 381a(F[$e
try{ Ev adY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P;.j5P^j`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5crd.1@^
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0X.(BRI~6p
fileFetch.start(); eXB'>#&s
} ?AMn>v
catch(Exception e){e.printStackTrace ();} ?X'm>R. @
2pKkg>/S
G?p !*7N
} p_^Jr*Mv
=;hz,+
?pE)K<+Zkf
public static void main(String[] args) g4Y1*`}2f
{ m?Tv8-1
new TestMethod(); C`4m#
} %rU8^'Gu
} ;\[n{<
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