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)); h1H$3TpP
} F`La_]f?b\
for(int i=0;i<nEndPos.length-1;i++) $V!25jQ
{ {FX]1:
nEndPos = nStartPos[i+1]; }eF r,bJ
} S5kD|kJ
nEndPos[nEndPos.length-1] = nFileLength; 0NK|3]p
} ~{GTL_w
} h=qT@)h1>
W^7yh&@lU
p~NHf\
//启动子线程 =W&m{F96
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S['cX ~
for(int i=0;i<nStartPos.length;i++) }'?qUy3x
{ :T|9;2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6$0<&')Yb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5dhy80|g]
nStartPos,nEndPos,i); 6#AEVRJKU@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _Hd|y
fileSplitterFetch.start(); 2;j<{'
} N:CQ$7T{ j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lSBR(a<\y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [Y~~C J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V1,/qd_
nEndPos = " + nFileLength); '9=b@SaAj
// fileSplitterFetch[nPos.length-1].start(); m)LI| v
^^zj4 }On?
{6WG
//等待子线程结束 BU4IN$d0Po
//int count = 0; wdAKU+tM
//是否结束while循环 Te[v+jgLY,
boolean breakWhile = false; VdGVEDwz
V0rQtxE{F
SO.u0!
while(!bStop) a5R. \a<q
{ 8sU5MQ5
write_nPos(); wP*3Hx;S
Utility.sleep(500); C #iZAR
breakWhile = true; 7y&6q`y E
G0|}s&$yL
w/O'&],x
for(int i=0;i<nStartPos.length;i++) N$=9R
{ Y<u%J#'[
if(!fileSplitterFetch.bDownOver) !tt 8-Y)i
{ }^0'IAXi
breakWhile = false; .d}yQ#5z
break; BC/5bA
} UWEegFq*
} rAAx]nQ@
if(breakWhile) 3cgq'ob
break; z@,(^~C_
6)ibXbH
AWi>(wk<
//count++; $ZGup"z)
//if(count>4) 5I,NvHD4
// siteStop(); U3z23LgA
} 8b.k*,r>
&Z[+V)6,,
`,xO~_ e>
System.err.println("文件下载结束！"); C3Q #[
} Jz>P[LcB
catch(Exception e){e.printStackTrace ();} R;pW,]}g,
} t6\H
O|+ZEBP
Jk-WD"J6
//获得文件长度 F<4:P=
public long getFileSize() |9%~z0
{ sZCK?
int nFileLength = -1; y705
try{ Y @'do)
URL url = new URL(siteInfoBean.getSSiteURL()); u-|%K.A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \t1#5
httpConnection.setRequestProperty("User-Agent","NetFox"); x%r$/=
]o]`X$n
&_-=(rK
int responseCode=httpConnection.getResponseCode(); w-ald?`
if(responseCode>=400) 5hy7}*dR
{ T@.+bD
processErrorCode(responseCode); BHAFO E
return -2; //-2 represent access is error 8tR6.09'
} y>0 @.
gh*k\0
Z(tJd,
String sHeader; -e(<Jd_=
~y"R{-%uS
0ZDm[#7z
for(int i=1;;i++) 9)]`le
{ d*Su c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q6$6:L,<
//Utility.log(in.readLine()); S+[,\>pY
sHeader=httpConnection.getHeaderFieldKey(i); }NwmZw>_
if(sHeader!=null) 5JVBDA^#om
{ ,&4 [`d
if(sHeader.equals("Content-Length")) w^&UMX}
{ qXq#A&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yC5>k;/6#K
break; uKXU.u*C
} *vRHF1)L
} nRqP_*]
else rwUhNth-Qh
break; 85io%>&0
} KYB3n85 1
} y@*4*46v
catch(IOException e){e.printStackTrace ();} ^Ff fc@=
catch(Exception e){e.printStackTrace ();} XS@iu,uO
}])j>E
gsQn@(;
Utility.log(nFileLength); l2Py2ZI-b
~oSA&v4V
KS~Q[-F1P
return nFileLength; '!Va9m*w7
} Q_,!(N
!K*3bY`#
4jZt0
//保存下载信息（文件指针位置） p +JOUW
private void write_nPos() ~8k`~t!
{ md{1Jn"
try{ 7]L}~
output = new DataOutputStream(new FileOutputStream(tmpFile)); u];\v%b
output.writeInt(nStartPos.length); C|FI4/-e
for(int i=0;i<nStartPos.length;i++) j/uMSE
{ U/U_q-z]
// output.writeLong(nPos); [C 7X#|
output.writeLong(fileSplitterFetch.nStartPos); _%rkN0-(a
output.writeLong(fileSplitterFetch.nEndPos); r7U[QTM%
} js)E:+{A,
output.close(); UeBSt.
} 0\ j)!b
catch(IOException e){e.printStackTrace ();} :5^5l
catch(Exception e){e.printStackTrace ();} p'/%"
} {2g?+8L$Z
REJBm
#c<F,` gdi
//读取保存的下载信息（文件指针位置） uX7"u*@Q*~
private void read_nPos() "el3mloR8
{ ABtv|0K
try{ uZ1G,9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <3k9 y^0
int nCount = input.readInt(); i}:^<jDv?
nStartPos = new long[nCount]; bb/A}< zD
nEndPos = new long[nCount]; J(,gLl
for(int i=0;i<nStartPos.length;i++) S^e e<%-
{ G8W^XD
nStartPos = input.readLong(); ,tFLx#e#
nEndPos = input.readLong(); 4NFvX4
} F+Hmp\rM#
input.close(); J72kjj&C
} U3>ES"N
catch(IOException e){e.printStackTrace ();} ''EFh&F
catch(Exception e){e.printStackTrace ();} |2X+( F Ed
} =WFG[~8
ve/|"RB
^''3}<Ep
private void processErrorCode(int nErrorCode) )Oj%3
{ *zPz)3;
System.err.println("Error Code : " + nErrorCode); ? i|LO
} @F5QgO J&r
R?,XSJ
Fmrl*tr
//停止文件下载 _H2%6t/V
public void siteStop() CM%;r5
{ &>auW}r
bStop = true; %LdFS~
for(int i=0;i<nStartPos.length;i++) 24_/JDz
fileSplitterFetch.splitterStop(); b;(BMO,(
*3Ci4\Ew
pB]+c%\
} ->YF</I
} ZEU/6.
//负责部分文件的抓取 G?{uR6s>#
**FileSplitterFetch.java mt3j$r{_
*/ dr7ry"5Zq
package NetFox; uQg&A`4
FHu+dZ
OOX}S1lA
import java.io.*; =dI2j@}c
import java.net.*; '^6x-aeq[D
RV+0C&0ff
6Yx/m
public class FileSplitterFetch extends Thread { j%s:d(H`
'd 6z^Z6
w!^{Q'/,Q
String sURL; //File URL ?wS/KEl=O
long nStartPos; //File Snippet Start Position .Cf`D tK
long nEndPos; //File Snippet End Position tqe8:\1yK
int nThreadID; //Thread's ID &ffd#2f`@
boolean bDownOver = false; //Downing is over "*aL(R
boolean bStop = false; //Stop identical 9"~,ha7S$
FileAccessI fileAccessI = null; //File Access interface onAC;<w
;O7<lF\7o
U*6)/.J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException </8F
{ [8Zvs=1
this.sURL = sURL; "V/6 nuCo
this.nStartPos = nStart; eE-@dU?
this.nEndPos = nEnd; (>\w8]
nThreadID = id; &ahZ_9Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 42: 6=\
} As7Y4w*+
=9JKg4I6
mxV0"$'Fm
public void run() k9<P]%
{ }[OOkYF#r
while(nStartPos < nEndPos && !bStop) wfxg@<WR
{ xui.63/
2,X~a;+
Sc zYL?w^
try{ _*O^|QbM
URL url = new URL(sURL); AG$S;)Yl9c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }vbs6u
httpConnection.setRequestProperty("User-Agent","NetFox"); p|z\L}0
String sProperty = "bytes="+nStartPos+"-"; BM&.Tw|x
httpConnection.setRequestProperty("RANGE",sProperty); >wpC45n)9N
Utility.log(sProperty); 26,!HmtC
D|}%(N@sl
Rx22W:S=C.
InputStream input = httpConnection.getInputStream(); S=o1k
//logResponseHead(httpConnection); 02_%a1g
Ty21-0F
;U=RV&
byte[] b = new byte[1024]; n%>c4*t
int nRead; Tc DkKa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .*N,x0B(
{ SWYIQ7*
nStartPos += fileAccessI.write(b,0,nRead); %/o8-N|_[
//if(nThreadID == 1) EVW{!\8[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MW^,l=kqW)
} rVx%"_'*-
G02(dj
H\\0V.}!
Utility.log("Thread " + nThreadID + " is over!"); WvN!8*XFM
bDownOver = true; n\#RI9#\
//nPos = fileAccessI.write (b,0,nRead); L)5YX-?
} Ccw6,2`&
catch(Exception e){e.printStackTrace ();} ^;b$`*M1
} %8)GuxG*
} ^gwVh~j
0pWF\<IZ
o!`.LL%
//打印回应的头信息 8$:4~:]/
public void logResponseHead(HttpURLConnection con) ;hz"`{(JY
{ {CM%QMM
for(int i=1;;i++) 9OeY59 :
{ 3d^zLL
String header=con.getHeaderFieldKey(i); e5bRi0
if(header!=null) EROf%oaz=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;O*y$|+PA
Utility.log(header+" : "+con.getHeaderField(header)); M+X>!Os
else \$o!M1j
break; #<X+)B6t
} xF'9`y^]!@
} 36154*q
/lKgaq.
fLj#+h-!
public void splitterStop() M^\#(0^2@
{ #%4-zNS
bStop = true; c7mIwMhl~
} _ECWSfZ
%(GWR@mfC
`)`J
} eeX^zaKl]
x:W nF62
cD&53FPXC
/* T6[];|%W
**FileAccess.java F V8K_xj
*//文件访问(定位，写) Y27x;U
package NetFox; {=WTAgP
import java.io.*; e_Na_l]
=W(mZ#*vdY
/3F4t V
public class FileAccessI implements Serializable{ Zgt:ZO
) -+u8#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .lVC>UT
RandomAccessFile oSavedFile; 0?} ),8v>
long nPos; Hi$J@xU
(9r\YNK
vdFy}#X
public FileAccessI() throws IOException iUl5yq
{ }W{rDc kv
this("",0); }D_h*9
} w=.w*?>
3.M<ATe^
!|hxr#q=4
public FileAccessI(String sName,long nPos) throws IOException iR;Sd >)
{ T `x:80
oSavedFile = new RandomAccessFile(sName,"rw"); ',L>UIXw
this.nPos = nPos; ^&oa\7<'
oSavedFile.seek(nPos); |QwX
} ">vxYi
xc[LbaBG
%Q:i6 ~
public synchronized int write(byte[] b,int nStart,int nLen) UxI0Of&:
{ dI'cZt~n
int n = -1; O,(p><k$/
try{ Fm(~Vt;%u
oSavedFile.write(b,nStart,nLen); nN!/
n = nLen; @!z9.o;
} 1"J\iwN3
catch(IOException e) LB}y,-vX>
{ _:ypPRJ
e.printStackTrace (); 2 2K:[K
} t]?u<KD<
MxMrLiqU6l
C2RR(n=N^
return n; dIiQ^M
} 0{bGVLp
k,o|"9H
?3bUE\p
} b~?FV>gl
4:\1S~WW
Vy-N3L
/* iHy=92/Ww
**SiteInfoBean.java ,H!E :k
*/ `OzcL
package NetFox; jUjgxP*7m
4%wP}Zj#
6u>${}
public class SiteInfoBean { v;.7-9c*
2O\p`,.
]jNv}{
private String sSiteURL; //Site's URL fD1J@57
private String sFilePath; //Saved File's Path m89-rR:Kc
private String sFileName; //Saved File's Name 3=w$1.B d
private int nSplitter; //Count of Splited Downloading File +*"u(7AV
iB#xUSkS
j:'sbU
public SiteInfoBean() ceN*wkGyB
{//nSplitter的缺省值为5 }C1&}hZ
//default value of nSplitter is 5 S]3K5Z|
this("","","",5); JR/:XYS+
} ((i%h^tGa;
(.~#bl
gMe)\5`\Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ta`}}I
{ G+Ft2/+\
sSiteURL= sURL; A[QUFk(
sFilePath = sPath; [@"~'fu0
sFileName = sName; L{y%\:]
this.nSplitter = nSpiltter; 9\9:)q
_t[RHrs
0BF'@r";
} ]?!#*<t r
3F fS2we
}F3}-5![
public String getSSiteURL() m\QUt ;
{ )}QtK+Rq
return sSiteURL; ZmSe>}B=
} 1<y(8C6
LWG%]m|C
C3EQzr`
public void setSSiteURL(String value) _*\:UBZx6
{ F_>OpT
sSiteURL = value; b1An2e[
} r8.R?5F@
v@_}R_pX
T,z7U2O
public String getSFilePath() uE{r09^q\
{ s~N WJ*i
return sFilePath; m-V_J`9"
} BYjEo
)b^yAzL?
fTb&k;'LR<
public void setSFilePath(String value) ;2Aqztp
{ $tKz|H)
sFilePath = value; QD6<sw@]P
} u-v/`F2wN
4%k{vo5i
XcN"orAo
public String getSFileName() 0hJ,l.
{ Mn`);[
return sFileName; sa8Q1i&%
} b;kgP`%%
L\)GPTo!x
#8xP,2&zf
public void setSFileName(String value) jL^3/0"o
{ -^C^3pms
sFileName = value; B=vBJC)
} SSCyq#dl$
_.)6~
_JEe]
public int getNSplitter() /6Bm <k%
{ r.WQ6h/eZ5
return nSplitter; i n$~(+
} o8uak*"{
4i]h0_]
qYba%g9RN(
public void setNSplitter(int nCount) 4$~A%JN3
{ mz-sazgV
nSplitter = nCount; 5/w4[d
} GXk]u
} qDlh6W?}k
_bsAF^ ;
TzSEQS{
/* A,PF#G(
**Utility.java 3Gk\3iU!
*/ h^ o@=%b
package NetFox; J 2H$ALl
zWO!z=
Z;'5A2
public class Utility { NCX`-SLv
p;xMudM
Y|X!da/
public Utility() d?6\
{ #MyF 1E
f%[0}.wp
'QOV!D
} SJ7-lben3
s#BSZP
//线程睡眠 xoe/I[P]U
public static void sleep(int nSecond) JHJIjYG>P
{ xofxE4.
try{ q9gk:Jt
Thread.sleep(nSecond); -`cNRd0n
} wn Q% 'Eo
catch(Exception e) ZCAg)/
{ `Lj'2LoER
e.printStackTrace (); boeIO\2}P0
} ?910ki_
} E0t%]?1
?{]"UnyVE*
//日志 [1Q:
public static void log(String sMsg) {>h,@
{ O5v~wLx9e
System.err.println(sMsg); H tx)MEZ
} 6^QSV@N|
j V'~>
BK 9+fO
public static void log(int sMsg) }$oZZKS
{ GhC%32F
System.err.println(sMsg); Z}`A'#!
} uB;PaZG?{
} 5E!Wp[^
OrRU$5Lo
}>yQ!3/i
/* Q`HG_n@?
**TestMethod.java y{9<>28
*/ ]L;X Aj?
package NetFox; 7J|eL yj
>jRH<|Az
l0BYv&tu
public class TestMethod { 7n*[r*$
Vs~!\<?
SB\T iH/
public TestMethod() t ]yD95|
{ ///xx/weblogic60b2_win.exe KD)+&69
try{ b+3QqbJ[F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AB1,G|L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~[d|:]
SiteFileFetch fileFetch = new SiteFileFetch(bean); qH-':|h7
fileFetch.start(); [r"`rBw
} _ZD8/?2QV
catch(Exception e){e.printStackTrace ();} __N#Y/e ]
f}U@e0Lsb
}9,^=g-
} eFiUB
98^o9i
}FoO
public static void main(String[] args) e$+/;MRq
{ 3Az7urIY
new TestMethod(); lqe71](sK8
} qe\JO'g#e
} ywS2`(
点击下载更多相关资料