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)); gB<p
} tGD$cBE
for(int i=0;i<nEndPos.length-1;i++) ;'pEzz?k"
{ g?i_10Xlp
nEndPos = nStartPos[i+1]; `a2Oj@jP
} 0pu])[P]_[
nEndPos[nEndPos.length-1] = nFileLength; -2tX 15,
} ^#S
} A A<9XC
:%A1k2
ix]3t^
//启动子线程 @^;WC+\0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r[M]2h
for(int i=0;i<nStartPos.length;i++) '8k\a{t_z
{ (1(3:)@S6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mw`%xID*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \J-O b
nStartPos,nEndPos,i); ?i(Tc!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pp#Kb 2*
fileSplitterFetch.start(); w])bQ7)
} 4I^6[{_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F)_Rs5V:(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?YgK]IxD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4\2p8__
nEndPos = " + nFileLength); +]CKu$,8
// fileSplitterFetch[nPos.length-1].start(); IVkKmO(qO
bR*T}w$<
$z{HNY*2
//等待子线程结束 QD<^VY6
//int count = 0; !V@Y \M d
//是否结束while循环 cWp n/.a
boolean breakWhile = false; Iu(T@",Q#
YT,1E>rd
>H5BY9]I
while(!bStop) v>)[NAY9
{ Y#{KGVT<
write_nPos(); ',6QL4qV/
Utility.sleep(500); <W/-[ M
breakWhile = true; =t&B8+6
*xU^e`P
n1uJQt
for(int i=0;i<nStartPos.length;i++) v2EM| Q xp
{ w>H!H6Q
if(!fileSplitterFetch.bDownOver) 6l [TQ
{ lbT<HWzNH
breakWhile = false; %MbjKw
break; ,$vc*}yI0
} 4VaUa8 D
} +2B{"Czm
if(breakWhile) k%:]PQjYT
break; Tr/wG
Q-O:L
qJ"dkT*
//count++; 9qwVBu ;
//if(count>4) $NG}YOP)@
// siteStop(); `z5j
} ;-^WUf|
%'4dgk
jDgiH}
System.err.println("文件下载结束！"); na $z\C\
} vT%rg r
catch(Exception e){e.printStackTrace ();} p5)A"p8"9,
} y @Y@"y
s.C-II?e
!S%XIq}FX
//获得文件长度 yql+N[
public long getFileSize() og.dYs7W4
{ : [aUpX=
int nFileLength = -1; A+Y>1-=JO
try{ I g-VSQ
URL url = new URL(siteInfoBean.getSSiteURL()); Ao`9fI#q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;n7k_K#0z!
httpConnection.setRequestProperty("User-Agent","NetFox"); F2oY_mA
&E {/s
-Q 6W`*8
int responseCode=httpConnection.getResponseCode(); cy^6g?ew
if(responseCode>=400) ;c:vzF~Q
{ 4^70r9hV9
processErrorCode(responseCode); fgn*3 pg
return -2; //-2 represent access is error .yi.GRk
} xE;fM\7pu
9N=Dls
X_Y$-I$qd
String sHeader; ,!%[CpM3
$3Wl~ G}
X[NsdD?w1+
for(int i=1;;i++) kfm8F8sxl
{ jW2z3.w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pl q$t/.U;
//Utility.log(in.readLine()); VC>KW{&J0
sHeader=httpConnection.getHeaderFieldKey(i); OYG8%L
if(sHeader!=null) 7gD$Q
{ W1r-uR
if(sHeader.equals("Content-Length")) @U5+1Hjc
{ _jU6[y|XLh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /o8`I m
break; )u\"xxcV
} <&l3bL
} \e'>$8%T
else V%e'H>EC
break; YaSwn3i/@S
} v[m/>l2[P
} Z9=Cw0( w?
catch(IOException e){e.printStackTrace ();} Lk#u^|Eq7=
catch(Exception e){e.printStackTrace ();} e *;"$7o9
mtmBL2?
_a15R/S
Utility.log(nFileLength); j]Rl1~+M
m>zUwGYEu
us`hR!_
return nFileLength; JguE#ob2
} IO^O9IEx,
oPzt1Y
-BQM i0
//保存下载信息（文件指针位置） d<7xSRC
private void write_nPos() x-y=Jor
{ QhpE2ICU
try{ 0lmoI4bW}s
output = new DataOutputStream(new FileOutputStream(tmpFile)); YfxZ<
output.writeInt(nStartPos.length); UvQxtT]
for(int i=0;i<nStartPos.length;i++) A"_;.e`
{ ;M"hX
// output.writeLong(nPos); ;EFs2-{K
output.writeLong(fileSplitterFetch.nStartPos); O_F<VV*MFQ
output.writeLong(fileSplitterFetch.nEndPos); `Ph4!-6#
} ]7dm`XV
output.close(); {r'#(\
} /Pg66H#RUf
catch(IOException e){e.printStackTrace ();} Sw'DS
catch(Exception e){e.printStackTrace ();} $`l- cSH;
} #Y`U8n2F
tTWYlbDFN
c/T]=S[
//读取保存的下载信息（文件指针位置） Z33wA?9
private void read_nPos() apGf@b
{ VWLou jB
try{ bmt2~!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c?<FMb3]
int nCount = input.readInt(); rf)\:75
nStartPos = new long[nCount]; 5"XcVH4g
nEndPos = new long[nCount]; oh& PQ{
for(int i=0;i<nStartPos.length;i++) {T:2+iS9:
{ aeH 9:GQ6
nStartPos = input.readLong(); 7|,5;
nEndPos = input.readLong(); InPq1AH
} UnW,|n8
input.close(); R['qBHQ?
} _4%+TN6z
catch(IOException e){e.printStackTrace ();} V\ARe=IWM
catch(Exception e){e.printStackTrace ();} og2]B\mN4
} Fo;xA
I"T_<
Vs{|:L+
private void processErrorCode(int nErrorCode) /:U\U_j
{ sFCoRH|"c
System.err.println("Error Code : " + nErrorCode); lQ!6n
} !u\X,.h
Wv(VV[?/&
YM1@B`yWE
//停止文件下载 $[FO(w@f
public void siteStop() hz\7Z+$L_
{ #@y4/JS&2
bStop = true; ^P&y9dC.
for(int i=0;i<nStartPos.length;i++) p(U'c}@2
fileSplitterFetch.splitterStop(); 'Ur$jW
)W*S6}A
8#7z5:_
} !\?? [1_e
} v9M;W+J
//负责部分文件的抓取 "hs`Y4U
**FileSplitterFetch.java #{ `(;83
*/ Nv #vfh9}P
package NetFox; #G9S[J=xe
Q3z-v&^E9
QabF(}61
import java.io.*; fS!%qr
import java.net.*; #\t?`\L3
RUO,tB|(_;
6I_W4`<VeZ
public class FileSplitterFetch extends Thread { LRB#|PW
(kb^=kw#0
?N$
String sURL; //File URL ~poy`h'
long nStartPos; //File Snippet Start Position Ov?k4kJ
long nEndPos; //File Snippet End Position e[R364K
int nThreadID; //Thread's ID #XC\=pZX
boolean bDownOver = false; //Downing is over Zroj-3-X~
boolean bStop = false; //Stop identical qjUQ2d
FileAccessI fileAccessI = null; //File Access interface +s1mm c
Z$HYXm
j6IWdqXe
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Et`z7Q*e
{ bnUd !/;
this.sURL = sURL; =3/||b4c
this.nStartPos = nStart; *PZNZ{|m
this.nEndPos = nEnd; ` [@ F3x
nThreadID = id; ur*1I/v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d;;]+%
} R2t5T-8`c
#Du1(R
7c4\'dt#
public void run() cq@8!Eu w]
{ h7I_{v8
while(nStartPos < nEndPos && !bStop) IY,&/MCh
{ *>S\i7RET
\gj@O5rGP
}2V|B4
try{ s?E7tmaM
URL url = new URL(sURL); V><5N;w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -br/
httpConnection.setRequestProperty("User-Agent","NetFox"); e[w)U{|40
String sProperty = "bytes="+nStartPos+"-"; "E8-76n
httpConnection.setRequestProperty("RANGE",sProperty); 'iUfr@
Utility.log(sProperty); V:My1R0
<E$5LP;:
A[=)Zw "
InputStream input = httpConnection.getInputStream(); S37Bl5W
//logResponseHead(httpConnection); 65s|gfu/
)}n`MRDB
J%3S3C2*m
byte[] b = new byte[1024]; /e#_Yg
int nRead; u -CY-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,j9}VnW)
{ R;'Pe>
nStartPos += fileAccessI.write(b,0,nRead); UiaY0 .D
//if(nThreadID == 1) 3EF|1B/5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [g_f`ZJ=
} p4HX83y{
q9icj
'$q'Wl)
Utility.log("Thread " + nThreadID + " is over!"); jo{GPp}
bDownOver = true; RK"dPr
//nPos = fileAccessI.write (b,0,nRead); (#LV*&K%IC
} YX!%R]c%
catch(Exception e){e.printStackTrace ();} Aw9^}k}UfD
} 1&Nk
} 4vp,izNW
f>-OwL($P
73 D|gF*
//打印回应的头信息 QjF.U8
public void logResponseHead(HttpURLConnection con) " 0K5 /9
{ F}2U8O
for(int i=1;;i++) 5NBc8h7 V
{ @6}c\z@AxM
String header=con.getHeaderFieldKey(i); 0@^YxU[YN
if(header!=null) kM]?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XvZg!<*OH
Utility.log(header+" : "+con.getHeaderField(header)); Q5{i#F7nJm
else C4TJS,!1rH
break; 7cY_=X-?Y
} :}e*3={4
} T~=NY,n
2vu"PeU9
]0V~|<0c
public void splitterStop() !)_80O1
{ :=UeYm @
bStop = true; Lt|k}p@]
} UH.M)br
!|!:MYn
}oj$w?Ex
} Wi hQj
qRTxg%
)MmMs"Um
/* $zyY"yWRZ
**FileAccess.java <yE(p
*//文件访问(定位，写) 0[);v/@Ho
package NetFox; s|%mGt &L
import java.io.*; b3<<4Vf
g9'50<|J
l3b$b%0'
public class FileAccessI implements Serializable{ k]ptk^
tJbOn$]2"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CPFd 33
RandomAccessFile oSavedFile; -O^b
long nPos; ZTMzL%i
EX=+TOkAf
6=MejT
public FileAccessI() throws IOException P[% W[E<
{ 86vk"
this("",0); Rfeiv
} k "'q
!gW$A-XD
ZRsDn
public FileAccessI(String sName,long nPos) throws IOException $9M>B<]
{ 8/ZJkI
oSavedFile = new RandomAccessFile(sName,"rw"); leg@ia
this.nPos = nPos; TW:vL~L
oSavedFile.seek(nPos); k2,n:7
} V.:a6>]
DUM,dFIlvF
}\OLBg/
public synchronized int write(byte[] b,int nStart,int nLen) +\\*Iy'xK
{ Apa)qRJd
int n = -1; :&#hjeltt
try{ -r/#20Y
oSavedFile.write(b,nStart,nLen); el;^cMY
n = nLen; Ajs<a(,6
} -TjYQ
catch(IOException e) eLL>ThMyW
{ yL_-w/a
e.printStackTrace (); $6Nm`[V
} ]i=-/
2fFNJ
_+wv3? c"
return n; R]m`v: 9
} 3@XCP-`
9kH~+
C>:F4"0
} }8fxCW*|
rs=wEMq/
3!Rb{
/* &s\$&%|
**SiteInfoBean.java #fzvK+
*/ rRYP~ $c
package NetFox; ` {k>I^Pg
G0^23j
Y^2`)':
public class SiteInfoBean { {!o-y=
D7 [n^WtL
hG2btmBht
private String sSiteURL; //Site's URL |\XjA4j
private String sFilePath; //Saved File's Path /-8v]nRB
private String sFileName; //Saved File's Name DN&ZRA
private int nSplitter; //Count of Splited Downloading File 5R{ {FD`h
>Y1?`
7h&$^
public SiteInfoBean() 9c=Y+=<
{//nSplitter的缺省值为5 8}{';k
//default value of nSplitter is 5 agM.-MK
this("","","",5); slOki|p;
} %+Z0$Q
(+>+@G~o
C ])Q#!D|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {5#P1jlT
{ dY;^JPT
sSiteURL= sURL; `[jQn;
sFilePath = sPath; dV<M$+;s]
sFileName = sName; InH R>,
this.nSplitter = nSpiltter; cx_[Y
-l`@pklQ
6IctW5b
} QKwWX_3%Z]
J= ia
x +q"%9.c
public String getSSiteURL() *O)_D bj
{ 8v*>~E/0
return sSiteURL; >#$(M5&}-
} HvKueTQ
p<Ah50!B
p27A#Uu2}
public void setSSiteURL(String value) i74^J+xk
{ C$"jZcm,I
sSiteURL = value; v|?hc'Fj
} nxsQDw\hy
3+EJ%
2^ ^;Q:
public String getSFilePath() P>)-uLc~W
{ _ZzN}!Mye
return sFilePath; ,au64sH
} &VY;Al
=<O{t#]
+y6|Nq
public void setSFilePath(String value) tmRD$O%:
{ ojs&W]r0Z
sFilePath = value; i\3BA"ZX
} -102W{V/T
<^~Xnstl
j+Y4>fL$
public String getSFileName() u5H#(&Om
{ }<2F]UuR
return sFileName; Eh!%NeO
} p$?c>lim
$-=aqUU
HoH3.AY X
public void setSFileName(String value) @Sq=#f/=
{ 7@fd[
sFileName = value; !Ya +
} ~_8Ve\Y^/
B 0 K2Uw
Y@9L8XNP>
public int getNSplitter() TbIM{X
{ nd3]&occ
return nSplitter; x^+ C[%
} ~e 6yaX8S
O.&6J/
yZ0;\Tr*J
public void setNSplitter(int nCount) @ RTQJ+ms
{ Pu/0<Orp7
nSplitter = nCount; }td+F&l($V
} sx*1D9s_
} Jgtvia
2mu~hJ
f#eTi&w
/* wS``Q8K+dM
**Utility.java ~q4DePVE
*/ *VHBTO9
package NetFox; 4TwU0N+>
_q6+]
ua|qL!L+
public class Utility { h,FP,w;G
+}mj6I
6WceDY
public Utility() j"94hWb
{ 4fzq C)
QAygr4\X^
2-j|q6m5
} Qi=rhN`
T2Y`q'
//线程睡眠 R&ou4Y:DG
public static void sleep(int nSecond) lmH!I)5
{ rt^z#2$
try{ &sS k~:
Thread.sleep(nSecond); _j%Rm:m;<
} ,J}lyvkd
catch(Exception e) M8KfC!
{ / sH*if
e.printStackTrace (); Sw5H+!
} lz{>c.Ll[
} 1 _5[5K^
C>T6{$xkC
//日志 !~ -^s
public static void log(String sMsg) x-tA{_:
{ v|{*y
System.err.println(sMsg); X){F^1CT{
} {dMa&r|lp
f\r$T Nd6
HoRLy*nU
public static void log(int sMsg) 2mU}"gf[
{ _xUhDu%
System.err.println(sMsg); ]"/ *7NM
} ,l0s(Cg
} GExG1n-
,P auP~L
NA/+bgyuT>
/* * +OAc`8
**TestMethod.java zh/+1
*/ Bj@&c>
package NetFox; }Ecm
l\$C)q6O
QRdb~f;<hj
public class TestMethod { n8:2Z>
y:2o-SJn
q8kt_&Ij
public TestMethod() "hy#L 0\t
{ ///xx/weblogic60b2_win.exe "H G:by
try{ e}K;5o=I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P]6pPS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c$e~O-OVD?
SiteFileFetch fileFetch = new SiteFileFetch(bean); =WO{h48]
fileFetch.start(); xHD!8B)
} 3J(STIxg
catch(Exception e){e.printStackTrace ();} kY_UY~E
qZ1fQN1yG
0 ?2#SM
} j<l>+., U
E>4 \9
)$th${pd#v
public static void main(String[] args) Uj!L:u2b
{ 4 Qw;r
new TestMethod(); %+pXzw`B
} m|f|u3'z$
} 9R ugkGy
点击下载更多相关资料