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)); Svmy(w~m
} Y$_B1_
for(int i=0;i<nEndPos.length-1;i++) |Rk@hzM2S
{ 0GeTSFj
nEndPos = nStartPos[i+1]; WOap+
} TC*g|d @b
nEndPos[nEndPos.length-1] = nFileLength; #*Ctwl,T
} #"~<HG}bR/
} y<Ot)fa$
~c `l@:
57c8xk[.2
//启动子线程 q/,O\,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X \/#@T
for(int i=0;i<nStartPos.length;i++) NBGH_6DROw
{ e\L8oOk#r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z Iu'[U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )SGq[B6@I
nStartPos,nEndPos,i); x%B/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rx|pOz,:
fileSplitterFetch.start(); 4kx N<]
} 9yP;@y*d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'H;*W|:-]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iH@UTE;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Avb\{)s+
nEndPos = " + nFileLength); '`Hr}
// fileSplitterFetch[nPos.length-1].start(); x.$FNt(9
<LiPEo.R
#ABZ&Z
//等待子线程结束 tR$NRMZ.
//int count = 0; i/Zd8+.n$
//是否结束while循环 7%M_'P4 V
boolean breakWhile = false; wibNQ`4k
Q$"D]!G
FYQS)s
while(!bStop) ;2QP7PrSY
{ |A(Iti{v
write_nPos(); ]Y&VT7+Z
Utility.sleep(500); +ZP7{%
breakWhile = true; i83OOV$1J
f/?P514h
r~['VhI!;E
for(int i=0;i<nStartPos.length;i++) sW\!hW1*x
{ S_H+WfIHV'
if(!fileSplitterFetch.bDownOver) RViAwTvY
{ 8}:nGK|kx
breakWhile = false; FS.L\MjV]U
break; 5b7RYV
} ]`WJOx4
} $6IJP\
if(breakWhile) Nh+H9
break; 5z)~\;[ -
}Q+|W=2t
JBZ@'8eqi]
//count++; F#E3q|Q"BS
//if(count>4) @=u3ZVD
// siteStop(); om>KU$g
} Y'X%Aw;`
?a]mDx>xh
)4;`^]F
System.err.println("文件下载结束！"); +=)+'q]S
} jebx40TA3
catch(Exception e){e.printStackTrace ();} qH_Dc=~la
} 1$ {SRU7l
u*9V&>o
rytyw77t(
//获得文件长度 1o>xEWt:0K
public long getFileSize() veECfR;
{ 47/iF97
int nFileLength = -1; tZo} ;|~'
try{ '|=;^Z7.K
URL url = new URL(siteInfoBean.getSSiteURL()); zm;C\s rF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GC'O[q+
httpConnection.setRequestProperty("User-Agent","NetFox"); 2X&qE}%k S
[2cD:JL
_@/8gPT*i
int responseCode=httpConnection.getResponseCode(); j] [,J49L
if(responseCode>=400) k9F=8q
{ c&Q$L }
processErrorCode(responseCode); /Z4et'Lo
return -2; //-2 represent access is error ?aMOZn?
} 69.NPy@
TD_Oo-+\
*Pg2c(Vg
String sHeader; hE-M$LmN@
/qw.p#
PPsE${!
for(int i=1;;i++) \l3h0R
{ vZ Lf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "kFg
//Utility.log(in.readLine()); e96k{C`j0
sHeader=httpConnection.getHeaderFieldKey(i); _SkLYL!=9
if(sHeader!=null) akQ7K
{ }ad|g6i`
if(sHeader.equals("Content-Length")) [Vt\$
{ 8dhUBJ0_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =vhm}
break; <a+Z;>
} QmIBaMI#
} a'IdYW0
else ? =+WRjF
break; E_LN]v
} I2Yz#V<%ru
} Z/J y'$x
catch(IOException e){e.printStackTrace ();} #$y?v%^
catch(Exception e){e.printStackTrace ();} T[A69O]v
Ga'swP=hf
WX0tgXl
Utility.log(nFileLength); ?z u8)U
ig &Y
E4xa[iZ
return nFileLength; !f6(Zho
} LreP4dRe
Y nZiTe@
/u+e0BHo
//保存下载信息（文件指针位置） n'w.; q
private void write_nPos() ReeH@.74
{ :\U{_@?`%
try{ g=o4Q< #^y
output = new DataOutputStream(new FileOutputStream(tmpFile)); B7vpsSL
output.writeInt(nStartPos.length); @s^-.z
for(int i=0;i<nStartPos.length;i++) #3d(M
{ 7VI*N)OZ8
// output.writeLong(nPos); @\I#^X5lv
output.writeLong(fileSplitterFetch.nStartPos); Rws3V"{`[
output.writeLong(fileSplitterFetch.nEndPos); -Y;3I00(
} *uvQ\.
output.close(); )sp+8
} FC"8#*x
catch(IOException e){e.printStackTrace ();} :eLVC7'
catch(Exception e){e.printStackTrace ();} wec)Ctj+
} lb1Xsgm{
2f_:v6
s"?3]P
//读取保存的下载信息（文件指针位置） b>9>uC@J15
private void read_nPos() 8-6L|#J#
{ =mmWl9'mJ
try{ b<u3 hln%,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HUOj0T
int nCount = input.readInt(); xn|(9#1o
nStartPos = new long[nCount]; PnG-h~Y3N
nEndPos = new long[nCount]; N)>ID(}F1
for(int i=0;i<nStartPos.length;i++) Zj4Uak
{ GowH]MO
nStartPos = input.readLong(); jlg(drTo
nEndPos = input.readLong(); >&#)Tqt!?
} H 7 ^/q7
input.close(); *_g$MI
} YT8F#t8
catch(IOException e){e.printStackTrace ();} dnuu&Rv
catch(Exception e){e.printStackTrace ();} ;ovP$ vl>
} NW)1#]gg%
H7+,*
& "B=/-(
private void processErrorCode(int nErrorCode) Jpo(Wl
{ D7qOZlX16
System.err.println("Error Code : " + nErrorCode); 8e"gW >f
} /vb`H>P
-s'-eQF J
mlS$>O_aX
//停止文件下载 ?b5^
public void siteStop() !$>R j
{ j$5LN.8J
bStop = true; eKqk= (
for(int i=0;i<nStartPos.length;i++) EAby?51+
fileSplitterFetch.splitterStop(); F1Bq$*'N$w
y L~W.H
d8x;~RA
} ?@ $r
} `pZm?}K
//负责部分文件的抓取 fLAw12;^
**FileSplitterFetch.java ;P&OX5~V
*/ E q+_&Wk
package NetFox; 7i1q wRv
eGbGw
@gXx1hEg
import java.io.*; b*Q&CL
import java.net.*; r-/`"j{O!
5.J.RE"M
]:/Q]n^
public class FileSplitterFetch extends Thread { 01(AK%e
*siFj CN<
R,=fv
String sURL; //File URL iMRwp+$
long nStartPos; //File Snippet Start Position '(jG[ry&T
long nEndPos; //File Snippet End Position [;myHI`tw
int nThreadID; //Thread's ID QnX(V[
boolean bDownOver = false; //Downing is over %C_HXr@
boolean bStop = false; //Stop identical ',5ky{
FileAccessI fileAccessI = null; //File Access interface =zs`#-^8
]L}dzA?:
j^2j&Ta
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v1,oilL
{ DkAAV9*
this.sURL = sURL; yyy|Pw4:Z
this.nStartPos = nStart; I[X772K
this.nEndPos = nEnd; &~U ]~;@
nThreadID = id; B@ KQ]4-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ('p5:d
} P J[`|
R0
K@w{"7}
public void run() 0NX,QD
{ b9dLt6d
while(nStartPos < nEndPos && !bStop) 0%I=d
{ I4?5K@a
D*|Bb?
! #2{hQRu
try{ ayF\nk4b
URL url = new URL(sURL); t}/( b/VD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2P{Gxz<#
httpConnection.setRequestProperty("User-Agent","NetFox"); [Cv/{f3]u{
String sProperty = "bytes="+nStartPos+"-"; I?G:p+
httpConnection.setRequestProperty("RANGE",sProperty); r1RM
Utility.log(sProperty); 5bpEYW+
R<N ]B
|*tp16+6
InputStream input = httpConnection.getInputStream(); k~ /Nv=D
//logResponseHead(httpConnection); (Px OE
Vj>8a)"B5a
sZF6h=67D
byte[] b = new byte[1024]; <0q;NrvUb
int nRead; v0jgki4t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ] {HI?V
{ /%A*aGyIc
nStartPos += fileAccessI.write(b,0,nRead); ZbAcO/
//if(nThreadID == 1) [Hh9a;.*}h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x0:m-C
} e'b(gD}
W-zP/]Dh
mF^v~
Utility.log("Thread " + nThreadID + " is over!"); _n>,!vH
bDownOver = true; AbmAKA@
//nPos = fileAccessI.write (b,0,nRead); EG |A_m85
} e.V:)7Uc
catch(Exception e){e.printStackTrace ();} ^eYVWQ'
} LTx,cP
} 0F><P?5
yd`mG{Z
'u<juFr
//打印回应的头信息 y;@:ulv[
public void logResponseHead(HttpURLConnection con) [RTs[3E^
{ @@%.t|=
for(int i=1;;i++) QWHug:c
{ 3"KCh\\b
String header=con.getHeaderFieldKey(i); >[=^_8M
if(header!=null) 9j:"J` '
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C#Iybg
Utility.log(header+" : "+con.getHeaderField(header)); )gy!GK
else QbpFE)TYJ|
break; D]Xsvv #
} 55c|O
} r#]WI|
$,Yd>%Y
`XEr(e9
public void splitterStop() pgZXJ
{ Whf.fK
bStop = true; _X"N1,0
} **gXvTqI
o"R7,N0rB
LW_f
} MfQ?W`Kop
)iK6:s#
pOG1jI5<{8
/* .$)
**FileAccess.java 2Ny"O.0h
*//文件访问(定位，写) 7,9=uk>0\
package NetFox; M,mvys$
import java.io.*; L"Olwwmk
8k1Dj1@0z
^iw'^6~
public class FileAccessI implements Serializable{ Jidwt$1l(
a8Nh=^Py
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mmRJ9OhS
RandomAccessFile oSavedFile; =k`Cr0aPF
long nPos; h6`6tk
UVIKQpA]A
uT7B#b7
public FileAccessI() throws IOException gz#i.-
{ q2:6QM&
this("",0); h Pa_VrH
} ]R9HyCl&a6
xw2[d+mB
AvV|(K"
public FileAccessI(String sName,long nPos) throws IOException 'AEE[
{ 56-dD5{hxR
oSavedFile = new RandomAccessFile(sName,"rw"); {v;&5!s
this.nPos = nPos; o:P}Wg/NK
oSavedFile.seek(nPos); .rqhi
} @>>~CZ`l
bsA-2*Q+
3/W'V,5G6
public synchronized int write(byte[] b,int nStart,int nLen) 3c6b6
{ 4s{~r
int n = -1; (uZ&V7l
try{ wLJ:\_Jaf
oSavedFile.write(b,nStart,nLen); "J8vjr1/
n = nLen; 0Bi.6r
} e5*hE
catch(IOException e) OL,TFLn4
{ ^qQZT]
e.printStackTrace (); |My4SoOF
} \k!{uRy'
!SdSE^lz`
E+g@M8D
return n; % *INT
} NmJWU:W_@
hD*SpVIU
YhE+W
} WE.{p>
ll.N^y;a
Jx7C'~,J
/* H0`]V6+<f
**SiteInfoBean.java -0{r>,&Mm
*/ #S*/bao#
package NetFox; |\IN.W[EL
K<Iv:5-2
4\u1TYR
public class SiteInfoBean { "x*egI
PV\+P6aIb
^^as'Dk
private String sSiteURL; //Site's URL }Nm#q@o$P
private String sFilePath; //Saved File's Path jiS_G%G
private String sFileName; //Saved File's Name fc-iAj
private int nSplitter; //Count of Splited Downloading File ]J$eDbaEjT
>\=3:gb:
"wnzo,
public SiteInfoBean() dj7hx"BI
{//nSplitter的缺省值为5 p,>5\Zre~
//default value of nSplitter is 5 Et/\xL
this("","","",5); @As[k2
} c[4i9I3v
`e|0g"oP
EGzzHIZ`!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (b~T]3Es
{ 6ZG+ZHUC&
sSiteURL= sURL; !1DKLQ
sFilePath = sPath; =JbRu|/
sFileName = sName; dq&yf7
this.nSplitter = nSpiltter; vAh6+K.e
,3p~w5C/+[
BJsz2t :0
} W;L7SF g)
C|).;V&
F{Jw^\
public String getSSiteURL() NOiN^::m
{ ,p2s:&"
return sSiteURL; KgiJUO`PR
} Yu[ t\/
f~y%%+{p
>x+6{^}Q>
public void setSSiteURL(String value) o` ZQd,3
{ Avd ^
sSiteURL = value; )d1_Wm#B
} ,PuL{%PXu
r1.nTO%
zHL@i0>^
public String getSFilePath() ICs\ z
{ %g$V\zmU
return sFilePath; /VS[pXXT|
} ,dov<U[ia
(-xS?8x$
NI#:|}CYS
public void setSFilePath(String value) ,5kKimTt
{ 7;sj%U^'l
sFilePath = value; bRJMYs
} 1+qw$T
t2"O
qnJt5
public String getSFileName() ?NR A:t(}
{ wF,UE_
return sFileName; iH@yCNE"
} VsgE!/>1
qY<'<T4\
6c"0})p
public void setSFileName(String value) +5o8KYV
{ =Z+nz^'b
sFileName = value; $8xl#SqH
} zb}9%.U
:xD=`ib
v!Pb`LCqK
public int getNSplitter() /<}m? k\
{ >.'*)@vQi
return nSplitter; Nz+949X
} rI>aAW'
8lb%eb]U
SAK!z!t
public void setNSplitter(int nCount) L%K\C
{ c^u"I'#Q
nSplitter = nCount; /X(t1+
} 8X`tU<Ab
} Y/ee~^YxK'
`m?c;,\
qT"Q1xU[
/* Bck7\
**Utility.java m~Bl*`~M
*/ }L3oR
package NetFox; ]Nl=wZ#`
2viM)+
mc_ch$r!
public class Utility { 9@52Fg;mj
x2z;6)
W$rH"_@m
public Utility() < hO /jB
{ T/xp?Vq6/
2 :mn</z
I8<,U!$
} !+4cqO
079'(%
//线程睡眠 H(2]7dRS%
public static void sleep(int nSecond) Xn,v]$M!
{ \X&H;xnC5
try{ 6290ZNvr
Thread.sleep(nSecond); 7#U^Dx\yh
} mG`e3X6@-
catch(Exception e) T[4<R 5}
{ 1jPJw3"3h
e.printStackTrace (); N:tY":Hi
} X 9%'|(tL
} ;D s46M-s
x{,q]u /
//日志 m-DsY
public static void log(String sMsg) :l&V]}:7*
{ ^#1.l=s
System.err.println(sMsg); ?(m jx
} vR=6pl$|~~
J9Ou+6u(
9,_mS{+B
public static void log(int sMsg) ] GTAq
{ $:j G-r
System.err.println(sMsg); EV^~eTz
} -gas?^`
} .E&z$N
YJ/zU52JK~
;9ly'<up
/* nJ"YIT1K]p
**TestMethod.java ]%Nlv(
*/ H_Kj7(=&>
package NetFox; ?wF'<kEH
|),'9
+sx 8t
public class TestMethod { 6"t;gSt4
L%$|^T=%
E+tB&
public TestMethod() N, *m ,
{ ///xx/weblogic60b2_win.exe D?,#aB"
try{ M$d%p6Cv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bb`':3%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ppt2A6W
SiteFileFetch fileFetch = new SiteFileFetch(bean); 80Y\|)
fileFetch.start(); <~X>[PK<
} gEhN3(
catch(Exception e){e.printStackTrace ();} @]c(V%x
hj$e|arB
8kOKwEX
} ls`,EFF
+|{RE.DL
#E+gXan
public static void main(String[] args) o|iYd n\
{ c8M2 ^{O,`
new TestMethod(); aJe^Tp(
} ^eGNgE
} CWG6;NT6m
点击下载更多相关资料