http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); QP6z?j.
} DR k]{^C~
for(int i=0;i<nEndPos.length-1;i++) w`c0a&7
{ \4h>2y
nEndPos = nStartPos[i+1]; K-J|/eB
} |Z`M*.d+
nEndPos[nEndPos.length-1] = nFileLength; @gt)P4yE
} \8;Qv
} cS<TmS!
Qw24/DJK
Z69+yOJI
//启动子线程 N#(jK1`y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8{R_6BS
for(int i=0;i<nStartPos.length;i++) rQ9*J
{ )!'n&UxPo$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D4< -8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ss?]
nStartPos,nEndPos,i); m"lE&AM64p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UF@IBb}0
fileSplitterFetch.start(); #*!+b
} t*{,Gk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ![^EsgEB*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z 0~j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x}tKewdOSe
nEndPos = " + nFileLength); #F_'}?09%
// fileSplitterFetch[nPos.length-1].start(); FE/$(7rM
zuUT S[
i]it5
//等待子线程结束 <=q*N;=T,
//int count = 0; puFXPw.3
//是否结束while循环 +$>N]1
boolean breakWhile = false; G1}~.%J
1#grB(p?
p/r~n'g$
while(!bStop) {mNdL J
{ ?n!lUr$:y
write_nPos(); 4\p$4Hs}
Utility.sleep(500); ;aq`N}d
breakWhile = true; vG Y!4@[
Y4QLs^IdB
p3g4p
for(int i=0;i<nStartPos.length;i++) Xo2^N2I
{ Mv|vRx^b
if(!fileSplitterFetch.bDownOver) p1+7<Y:
{ |y.zocBj
breakWhile = false; r=h8oUNEJ*
break; K!GUv{fp
} Z[Wlyb0
} JW=uK$sO
if(breakWhile) Yt -W1vl
break; @4;&hP2Z:
m7JPH7P@BM
h~ $&
//count++; 4[`[mE18.
//if(count>4) {5>3;.
// siteStop(); - $%jb2
} r,5-XB
$4=Ne3y
7'Lp8
System.err.println("文件下载结束！"); >A3LA3( c
} }/20%fP
catch(Exception e){e.printStackTrace ();} y =R aJm
} NdZ)[f:2
0f1H8zV
P*0f~eu
//获得文件长度 wTTRoeJ}
public long getFileSize() 9hy'DcSy,
{ XM$GQn]B
int nFileLength = -1; ~L~]QN\3
try{ u=%y
URL url = new URL(siteInfoBean.getSSiteURL()); @8|Gh]\P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hGvqT,'
httpConnection.setRequestProperty("User-Agent","NetFox"); ,s0 9B
@d&g/ccMxd
Rfht\{N 7
int responseCode=httpConnection.getResponseCode(); <KtBv Ip]
if(responseCode>=400) 5:c;RRn
{ sc%dh?m7
processErrorCode(responseCode); `4LJ;KC(
return -2; //-2 represent access is error aVP5%
} VUp. j
D3y>iQd
wS V@=)H\:
String sHeader; l8^y]M
q-YL]PgV
x@Y|v@}BE
for(int i=1;;i++) 6J\q`q(W(
{ |~eY%LB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L;3aZt,#O
//Utility.log(in.readLine()); [<yz)<<
sHeader=httpConnection.getHeaderFieldKey(i); PB+\jj
if(sHeader!=null) 5C B%=iL{
{ g92dw<$>
if(sHeader.equals("Content-Length")) Hq?&Qo
{ u#FXW_-TK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VgA48qZ
break; 0(8gQ 2n
} QWw"K$l
} ;u,rtEMy;
else ^#;RLSv
break; //<:k8
} p5-<P?B
} DwXU
catch(IOException e){e.printStackTrace ();} pw3(t
catch(Exception e){e.printStackTrace ();} S;8.yj-
6}ftBmv
;1@C_5C
Utility.log(nFileLength); ';6X!KY+]
^sV|ck
.Vmtx
return nFileLength; +8f>^*:u
} ~T02._E
+`| mJa
<7^Kt7k
//保存下载信息（文件指针位置） Ir27ZP
private void write_nPos() @0|nq9l1
{ z?kd'j`FG
try{ \-OC|\{32
output = new DataOutputStream(new FileOutputStream(tmpFile)); D"cKlp-I6|
output.writeInt(nStartPos.length); D^u\l
for(int i=0;i<nStartPos.length;i++) D-pX<0-y
{ >! oF0R_<
// output.writeLong(nPos); 1i3V!!r
output.writeLong(fileSplitterFetch.nStartPos); >$uUuiyL4
output.writeLong(fileSplitterFetch.nEndPos); "U{,U`@?
} pDOM:lGya
output.close(); oIb) Rq!m
} Y 9i][
catch(IOException e){e.printStackTrace ();} < eQ[kM
catch(Exception e){e.printStackTrace ();} 5mavcle{4r
} sLi*SR
3u_oRs
b@6:1x
//读取保存的下载信息（文件指针位置） Fc'[+L--Q
private void read_nPos() \5hw9T&[B
{ fLNag~
try{ o8{<qn|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W`x)=y]Z
int nCount = input.readInt(); 1~@|eWr|
nStartPos = new long[nCount]; RM,'o[%
nEndPos = new long[nCount]; OR;&TbWF(R
for(int i=0;i<nStartPos.length;i++) _R74/|
{ =Z`0>R`
nStartPos = input.readLong(); >A($8=+#x
nEndPos = input.readLong(); U Du~2%
} t8vc@of$c,
input.close(); ;&kn"b}G;
} iNJAZ6@+
catch(IOException e){e.printStackTrace ();} 6vobta^w
catch(Exception e){e.printStackTrace ();} \Yq0 zVol
} "0-y*1/m
qlUzr.^-
B+46.bIH
private void processErrorCode(int nErrorCode) ! =WcF5
{ h<Wg3o
System.err.println("Error Code : " + nErrorCode); ,QvYTJ{
} F7T E|LZ
TatMf;?h&
KO&:06V{
//停止文件下载 H&bh<KPMh
public void siteStop() 7/"@yVBW
{ yp+F<5o
bStop = true; P}@*Z>j:#
for(int i=0;i<nStartPos.length;i++) a#y{pT2 b
fileSplitterFetch.splitterStop(); dB3N%pB^
%S`ik!K"I
~ziexZ=N
} E>}q2
} JZ=5Bpw
//负责部分文件的抓取 {ma;G[!
**FileSplitterFetch.java 4SR(->@
*/ kA^A mfba
package NetFox; a,n93-m(m
gz61FW
5B*qbM
import java.io.*; $.:3$et@/
import java.net.*; fHfY}BQS
|I^y0Q:K
!SF^a6jT
public class FileSplitterFetch extends Thread { J8;Okzb!L
dy:d=Z
^ ulps**e
String sURL; //File URL K-(;D4/sQE
long nStartPos; //File Snippet Start Position d>!p=O`>{q
long nEndPos; //File Snippet End Position H$tb;:
int nThreadID; //Thread's ID 5v9uHxy
boolean bDownOver = false; //Downing is over N9]xJgTze
boolean bStop = false; //Stop identical 4ht\&2&:
FileAccessI fileAccessI = null; //File Access interface O]qPmEj
/9_#U#vhY
`?uPn~,e8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +< KNY
{ "}zda*z8
this.sURL = sURL; &fSTR-8ev#
this.nStartPos = nStart; xl2g0?
this.nEndPos = nEnd; LgHJo-+>
nThreadID = id; m r4b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "'A"U
} :woa&(wN;1
r)b<{u=]
{?i)K X^
public void run() a)S7}0|R
{ C).2gQ G
while(nStartPos < nEndPos && !bStop) O >FO>
{ Km*<Kfcz
lIh[|]
7Fl-(Nv`
try{ "H1:0p
URL url = new URL(sURL); Ei~f`{i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QlD6i-a
httpConnection.setRequestProperty("User-Agent","NetFox"); 7lU.Nit
String sProperty = "bytes="+nStartPos+"-"; 2U9&l1P=
httpConnection.setRequestProperty("RANGE",sProperty); %&<W(|U1<
Utility.log(sProperty); a)9rs\Is{
16$y`~c-z
&p"(-
InputStream input = httpConnection.getInputStream(); 3hS6jS
//logResponseHead(httpConnection); l h/&__
M<[?g5=#
CgnXr/!L
byte[] b = new byte[1024]; VXIQw'Cq
int nRead; XP;x@I#l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~>%DKJe
{ <xn;bp[
nStartPos += fileAccessI.write(b,0,nRead); de YyaV
//if(nThreadID == 1) |(ocDmd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z;b+>2oL
} A}G|Yfn
-3hCiKq
Q)^g3J
Utility.log("Thread " + nThreadID + " is over!"); ow.6!tl0=h
bDownOver = true; x~/+RF XF
//nPos = fileAccessI.write (b,0,nRead); onl>54M^
} g:gB`8w?
catch(Exception e){e.printStackTrace ();} ^\wl2
} inF6M8 A1
} A/ 0qk
J_ J+cRwq
[xdj6W
//打印回应的头信息 - DL"-%X.
public void logResponseHead(HttpURLConnection con) HXks_ix )
{ Q2\
for(int i=1;;i++) [rdsv
{ ',mW`ZN
String header=con.getHeaderFieldKey(i); S()Za@ [a$
if(header!=null) s[c^"@HT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )+Y&4Qu
Utility.log(header+" : "+con.getHeaderField(header)); hI~SAd ,#A
else !k<:k "7
break; ]rW8y%yD
} TnE+[.Qu
} /F~X,lm*~
+R[4\ hC0Y
J_xG}d
public void splitterStop() #@Y/{[s|@
{ 2k1aX~?
bStop = true; QnKC#
} _Bk U+=|J
)saR0{e0N
tWD|qg_
} 9?`RR/w
O9]\Q@M.
LSkk;)'2K
/* XDLEVSly7
**FileAccess.java i_U}{|j
*//文件访问(定位，写) kh?. K#
package NetFox; Eark)
import java.io.*; gyus8#sT
@@}`hii
zvf3b!}
public class FileAccessI implements Serializable{ [7W(NeMk
$a.u05
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _CdROo6I
RandomAccessFile oSavedFile; {}\CL#~y
long nPos; GLh]G(
D1X{:#|
^M Ey,
public FileAccessI() throws IOException BaL]mIx
{ A=`*r*
this("",0); <qY5SV,
} crn k|o
CLK^gZ
p4mY0Y]mP
public FileAccessI(String sName,long nPos) throws IOException ]T^is>
{ 6 =gp:I
oSavedFile = new RandomAccessFile(sName,"rw"); Hg(5S,O2
this.nPos = nPos; y\[r(4h
oSavedFile.seek(nPos); JO1 ,TtA
} Ew4g'A:H
x9V {R9_gf
ULl_\5s2
public synchronized int write(byte[] b,int nStart,int nLen) y1C/v:;
{ lbkLyp2
int n = -1; #T%zfcUj
try{ _413\`%8?
oSavedFile.write(b,nStart,nLen); xzk}[3P{
n = nLen; z="L4
} Y@}FL;3
catch(IOException e) D4Sh9:\
{ uva\0q
e.printStackTrace (); l$XA5#k
} XxOn3i
xo~g78jm7,
H;I~N*ltJ(
return n; Z.Pi0c+
} }gCHQ;U7`
POGw`:)A
M#M?1(O/NE
} |I1+"Mp
|Fv?6qw+
2k+16/T
/* -e*BqH2t
**SiteInfoBean.java v2J0u:#,
*/ :s*>W$Wp4
package NetFox; _4R,Ej}
{L9yhYw
j>!sN`dBj
public class SiteInfoBean { Kbas-</Si
"DjU:*'
`P.CNYR<J
private String sSiteURL; //Site's URL K^H>~`C=
private String sFilePath; //Saved File's Path Z[} $n-V
private String sFileName; //Saved File's Name "$8w.C
private int nSplitter; //Count of Splited Downloading File &;v!oe
;BI)n]L
YzV(nEW
public SiteInfoBean() K0<yvew
{//nSplitter的缺省值为5 k18$JyaG
//default value of nSplitter is 5 e&3#2_
this("","","",5); *Nlu5(z
} O5;-Om
o!Fl]3F
H#+xKYrp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tpU D0Z)
{ <SQ(~xYi
sSiteURL= sURL; QS\ x{<e/
sFilePath = sPath; }m_t$aaUc1
sFileName = sName; @^CG[:|
this.nSplitter = nSpiltter; {!=2<-Aq
r}EM4\r
uaxB -PZ
} :qnokrGzB
1nB@zBQu-
sqG`"O4W
public String getSSiteURL() J@` 8(\(
{ DHzkRCM
return sSiteURL; 7;xKy'B\
} q\H7&w
JZ K7uB,X
xG%*PNM0q
public void setSSiteURL(String value) F+*Q <a4
{ %6]\^
sSiteURL = value; 4oJ$dN
} U**)H_S/~
Nza; O[
J3&Sj{ o
public String getSFilePath() JS7dsO0;
{ (C\r&N
return sFilePath; *?N<S$m
} <E}N=J'uJ
)ddsyFGW
P6we(I`"2
public void setSFilePath(String value) +*a7GttU
{ IJIQ" s
sFilePath = value; ~:Ixmqi}R
} hbnS~sva
iGa}3pF
.. UoyBV
public String getSFileName() <[9?Rj@
{ (nz}J)T&
return sFileName; :c<*%*e
} SG`)PW?
~04[KG
)* 3bkKVB
public void setSFileName(String value) ,s? dAy5
{ Ff)@L-Y\K
sFileName = value; P;c0L;/
} 8[HZ@@
NL-_#N$
R&!]Rl9hf
public int getNSplitter() +-P<CCvWz
{ i[_|%'p
return nSplitter; o=mo/N4
} pK"&QPv
D1ZC&B_}-
/.v_N%*-v
public void setNSplitter(int nCount) 4d-q!lRpa
{ Hf_'32e3<
nSplitter = nCount; * gHCy4u{
} [`9^QEj
} *;X-\6
;NG1{]|Z
Gl;f#}
/* xFX&9^Uk
**Utility.java ['t8C
*/ 6KB^w0oA
package NetFox; /f]/8b g>
K @C4*?P
hiIyaWU
public class Utility { ,`"K
+,wWhhvlzv
_XWnS9
public Utility() <S{7Ro
{ e?1KbJ?.
m0C{SBn-M
0@v2*\D#
} UAKu_RO6S
lG 8dI\`
//线程睡眠 %r P !
public static void sleep(int nSecond) S;h&5.p
{ x97H(*
try{ wo]ks}9
Thread.sleep(nSecond); oX*b<d{\N
} Y2D>tpqNw
catch(Exception e) [%?hCc
{ sL8>GtVo
e.printStackTrace (); ;L$,gn5H
} d.I%k1`(
} g41<8^(
#@q1Ko!NZ
//日志 1~L\s}|2d
public static void log(String sMsg) 5f{wJb2
{ FR(QFt!g
System.err.println(sMsg); w_!%'9m>
} 2$Wo&Q^_
Onyh1
n5\}KZh
public static void log(int sMsg) w-M7opkq
{ >'.[G:b
System.err.println(sMsg); vuW-}fY;
} JeL~]F
} 18rp; l{
-`g J
2;h+;G
/* 1Df,a#,y"
**TestMethod.java %2,/jhHL
*/ :-U53}Iy
package NetFox; tStJ2-5*t
]6q*)q:`
St_Sl:m$
public class TestMethod { k1m'Ka-
^} tuP
s*eyTm
public TestMethod() }9 ?y'6l
{ ///xx/weblogic60b2_win.exe ]An_5J
try{ xjE7DCmA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _V&x`ks
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *cPN\Iu.W
SiteFileFetch fileFetch = new SiteFileFetch(bean); yduuFK
fileFetch.start(); wZ O@J|
} ^t7_3%%w
catch(Exception e){e.printStackTrace ();} 7<vy;"wB
!9PX\Xbn
8M~u_`6
} vU7&'ca
EFeAr@nj
A^t"MYX@
public static void main(String[] args) R7,pukK
{ B9AbKK$`
new TestMethod(); b70AJe=
} vLr&ay!w
} {x|MA(NO
点击下载更多相关资料