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)); ]AdL
} 6SmawPPP
for(int i=0;i<nEndPos.length-1;i++) -VRKQNT
{ }q[IhjD%
nEndPos = nStartPos[i+1]; o^&nkR
} !5h@uar
nEndPos[nEndPos.length-1] = nFileLength; \"hP*DJ"
} ,zH\&D$>u
} $iAd)2LT
GxcW^{;
7W\aX*]
//启动子线程 &Kc'g H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \jThbCb
for(int i=0;i<nStartPos.length;i++) Av^<_`L:
{ Z?tw#n[T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q?TXM1Bp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^G]H9qY-e
nStartPos,nEndPos,i); $79-)4;z4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9q f=P3
fileSplitterFetch.start(); CaqMLi%
} 7`Bwo*Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uNRT@@oCq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9$:+5f,%a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #sp8 !8|y
nEndPos = " + nFileLength); "f<+~
// fileSplitterFetch[nPos.length-1].start(); @jevY81)
OLM}en_L
Di8;Tq
//等待子线程结束 :*{\oqFn~$
//int count = 0; &C7HG^;W9
//是否结束while循环 h9L/.>CX
boolean breakWhile = false; p?zh4:\F+
1(12`3
j8"2K^h=
while(!bStop) d9sqO9Ud8
{ !2Q>
write_nPos(); z@n779i
Utility.sleep(500); bkfk9P
breakWhile = true; ]w[T_4l
[v$NxmRu
v<U +&D{
for(int i=0;i<nStartPos.length;i++) '+{dr\nJ
{ 3?R QPP
if(!fileSplitterFetch.bDownOver) 'uOzC"_yF
{ |]9Z#lv+I
breakWhile = false; %[C-KQH
break; >ey-j\_v
} 4C{3>BE
} K'zG[[P
if(breakWhile) fCxF3m(O
break; Z'I0e9Jw
d(-$ { c
E[RLBO[*n
//count++; =wy3h0k^
//if(count>4) Z*rA~`@K6
// siteStop(); /Aq):T T
} NJglONO
MjHjL~Tg
[o,S.!W8
System.err.println("文件下载结束！"); *jF VYg
} BsX# ~
catch(Exception e){e.printStackTrace ();} HBFuA.",
} $ (gR^L
U@$=0*
%aszZP
//获得文件长度 Hf'yRKACj
public long getFileSize() >xt*(j&}
{ 9#;UQ.qA
int nFileLength = -1; K{&b "Ba1
try{ *G{Zo*2< i
URL url = new URL(siteInfoBean.getSSiteURL()); O<x53MN^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j;k(AM<
httpConnection.setRequestProperty("User-Agent","NetFox"); Tcglt>tj"
^8V cm*
(1vmtg.O
int responseCode=httpConnection.getResponseCode(); Qp?n0WXZ
if(responseCode>=400) q$Ol"K@
{ pw7_j;}l
processErrorCode(responseCode); IrRn@15,
return -2; //-2 represent access is error .F~EQ %
} "F+Wo&
S %"7`xl
Ik#>6
String sHeader; YJ5;a\QxN
A*h)p@3t<
3\,TI`^C
for(int i=1;;i++) fuH Dif,
{ iDO~G($C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (!';
//Utility.log(in.readLine()); /N@0qQ
sHeader=httpConnection.getHeaderFieldKey(i); 2#Au6BvX
if(sHeader!=null) |yI?}zyR
{ n^/,>7J
if(sHeader.equals("Content-Length")) F|V co]"S1
{ 'Ph4(Yg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LwUvM
break; @T1>%oi
} |k'I?:'
} U[S;5xeF.j
else 2|~&x~
break; -X4`,0y%{O
} s=huOjKL]
} q9Y0Lk
catch(IOException e){e.printStackTrace ();} 9GZF39w u
catch(Exception e){e.printStackTrace ();} :;"3k64
B>47Ic
!9o8v0ZI
Utility.log(nFileLength); &TbnZnv
#G#gB
oRu S_X
return nFileLength; j7-#">YL
} c_^H;~^rL
l}AB):<Z
o7 !@WOeZ3
//保存下载信息（文件指针位置） dm$:xE":
private void write_nPos() 72-@!Z0e
{ V43JY_:
try{ "<O?KO3K
output = new DataOutputStream(new FileOutputStream(tmpFile)); NHc+QMbou(
output.writeInt(nStartPos.length); 5o~Z>
for(int i=0;i<nStartPos.length;i++) YgWnPp
{ P6=|C;[
// output.writeLong(nPos); fQx 4/4j
output.writeLong(fileSplitterFetch.nStartPos); |J}~a8o
output.writeLong(fileSplitterFetch.nEndPos); 9J]LV'f7
} \+Cp<Hv+
output.close(); d&'6l"${
} *gT TI;:
catch(IOException e){e.printStackTrace ();} \O/=g6w|t}
catch(Exception e){e.printStackTrace ();} +vbNZqwz
} A`r&"i OKA
!E7/:t4
2dI:],7
//读取保存的下载信息（文件指针位置） rz.`$b
private void read_nPos() z(%Zji@!N
{ zR<jZwo]#
try{ q{_buTARq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gVl#pVO`N
int nCount = input.readInt(); ss2:8up 99
nStartPos = new long[nCount]; IaF79}^
nEndPos = new long[nCount]; vMI\$E&
for(int i=0;i<nStartPos.length;i++) {jq-dL
{ [wOO)FjT
nStartPos = input.readLong(); D>1Dao
nEndPos = input.readLong(); )t.q[O`
} ?D~uR2+Z
input.close(); . }1!MK5
} 4v?S`w:6
catch(IOException e){e.printStackTrace ();} -FPl",f=r
catch(Exception e){e.printStackTrace ();} 2Vi[qS^
} FJ[(dGKeE
[p(C:rH
6RtpB\hq
private void processErrorCode(int nErrorCode) w5nRgdboy!
{ [zfGDMG&
System.err.println("Error Code : " + nErrorCode); C/$IF M<
} Av[jFk
F`N*{at
KG?]MVXA
//停止文件下载 bC{~/ JP
public void siteStop() \E30.>%,
{ Q7s1M&K
bStop = true; bd9c/>&
for(int i=0;i<nStartPos.length;i++) R3<+z
fileSplitterFetch.splitterStop(); aG ,uF
G@;aqe[dB
Xgm7>=l
} )Qc$UI8L
} Psv!`K
//负责部分文件的抓取 _Dv^~e1c
**FileSplitterFetch.java {xr]xcM'b
*/ E5dXu5+ye
package NetFox; Ob6vg^#
Q9'p2@Z
L9.#/%I\
import java.io.*; g,;MV7yE
import java.net.*; Uwp +w
O<hHo]jLF
x<l1s
public class FileSplitterFetch extends Thread { y{N9.H2
,y>Na{@Y
ymzm x$o=
String sURL; //File URL A_.QHUjpx
long nStartPos; //File Snippet Start Position { nV zN(
long nEndPos; //File Snippet End Position aI<~+]
int nThreadID; //Thread's ID }:%pOL n
boolean bDownOver = false; //Downing is over 1mX*0>
boolean bStop = false; //Stop identical =6sXZ"_Tw
FileAccessI fileAccessI = null; //File Access interface %Z7!9+<
E;qwoTmul
@2mP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZeeuH"A
{ (Ka#6
this.sURL = sURL; coWBKWF
this.nStartPos = nStart; Y[!a82MTzn
this.nEndPos = nEnd; Trrh`@R
nThreadID = id; 3\{Sf /#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _a&|,ajy>
} ZYA(Bg^
,:`6x[ +
"" U_|JH-
public void run() _#C}hwOR>X
{ )hug<D *h
while(nStartPos < nEndPos && !bStop) HhL%iy1
{ K>[H@|k\k
qC)VT3
`y}d)"!
try{ />C~a]}
URL url = new URL(sURL); 9QMn%8=j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X2cR+Ha0
httpConnection.setRequestProperty("User-Agent","NetFox"); R~~rqvLm
String sProperty = "bytes="+nStartPos+"-"; `xUPML-
httpConnection.setRequestProperty("RANGE",sProperty); >|?T|
Utility.log(sProperty); rHlF& ET
!qlGt)G3
(5~C _Y
InputStream input = httpConnection.getInputStream(); Z+"&{g
//logResponseHead(httpConnection); tWnm{mF
F"xO0t
B5:g{,C
byte[] b = new byte[1024]; prtxE&-
int nRead; -`OR6jd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KIo}Gd&
{ h '[vB^
nStartPos += fileAccessI.write(b,0,nRead); t\i1VXtO
//if(nThreadID == 1) Zjg\jo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u4@e=vWI
} "!tw ,Gp
Nb~dw;t
K//T}-Uub
Utility.log("Thread " + nThreadID + " is over!"); #OWs3$9
bDownOver = true; hXm}d\
//nPos = fileAccessI.write (b,0,nRead); 6;cY!
} L\NZDkd
catch(Exception e){e.printStackTrace ();} ,g_onfY
} R*Z]
} AwUc{h l<
OZD!#YI
H@E")@92
//打印回应的头信息 E[.tQ|C
public void logResponseHead(HttpURLConnection con) W@,p9=425
{ hF"g91P
for(int i=1;;i++) O}_a3>1DY
{ ttaQlEa=Z
String header=con.getHeaderFieldKey(i); {|Ki^8h/p
if(header!=null) cEc,eq|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >}b6J7_
Utility.log(header+" : "+con.getHeaderField(header)); zN+*R;Ds
else #we>75l{+R
break; pXh~#o6V
} s;2/Nc
} x$GsDV
sD8m<
VtO;UN
public void splitterStop() vX0"S
{ kq~[k.
bStop = true; Y#&0x_Z
} \c~{o+UD-
u:$x6/t
LkGf|yd_
} 6lmiMU&V
5 n+ e
4su_;+]
/* *Z`XG_s5
**FileAccess.java /.)[9bQ<
*//文件访问(定位，写) (X(1kj3
package NetFox; H5rPq_R
import java.io.*; Q_aqX(ig
{(Og/[
;wXY3|@
public class FileAccessI implements Serializable{ FU\/JF.j
oWDSK^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N pXgyD
RandomAccessFile oSavedFile; 5BHOHw D{
long nPos; ~J1;tZS
iog # ,
>H}jR[H'
public FileAccessI() throws IOException Jf?S9r5Q
{ Wk`bb!P_
this("",0); wKk 3)@il
} x^)g'16`
Y .
4r1<,{gCS
public FileAccessI(String sName,long nPos) throws IOException ]D LZ&5pv
{ K lli$40
oSavedFile = new RandomAccessFile(sName,"rw"); K[uY+!'1
this.nPos = nPos; JFRpsv
oSavedFile.seek(nPos); X<~k =qwA
} V)0[`zJ
'u(=eJ@1
Cs:+93w
public synchronized int write(byte[] b,int nStart,int nLen) D[89*@v
{ 1mHwYT+
int n = -1; -(\1r2 Y
try{ x0\e<x9s
oSavedFile.write(b,nStart,nLen); g.I(WJX0
n = nLen; qr)v'aC3
} EkJVFHfh
catch(IOException e) AqV09 $
{ =oE_.ux\
e.printStackTrace (); %cH8;5U40
} & u$(NbK
x37/cu
J| SwQE~
return n; ud0QZ X
} dqqnCXYuW
WD15pq l
6xH;:B)d
} >=if8t!
N'I(P9@
JY{X,?s
/* }@Xh xZu
**SiteInfoBean.java tNK^z7Dm
*/ `6&`wKz
package NetFox; t]s94 R q
Y!SE;N&
!*&4< _
public class SiteInfoBean { i<%m Iq1L
B!eK!B
B@-|b
private String sSiteURL; //Site's URL 9Ei5z6Vk/+
private String sFilePath; //Saved File's Path N83!C=X'
private String sFileName; //Saved File's Name xEjx]w/&
private int nSplitter; //Count of Splited Downloading File 3 m6$YWO
mge#YV::
&=G)NeT_
public SiteInfoBean() 6N"m?g*Z d
{//nSplitter的缺省值为5 F8;mYuA
//default value of nSplitter is 5 Zr=ib
this("","","",5); k@S)j<
} Gb;99mE
C>^,*7dS
".gNeY6)x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rn;<HT
{ z<!O!wX_aI
sSiteURL= sURL; ]DO&x+Rb
sFilePath = sPath; vd`O aM}#U
sFileName = sName; 42&v% ;R
this.nSplitter = nSpiltter; *ot>WVB
`?l3Ct*
"# !D|[h0
} 2`EVdl7B]
;`DD}j`
qe<Hfp/p
public String getSSiteURL() OZf6/10O/
{ e!GZSk
return sSiteURL; D93gH1z
} msiu8E
3f"C!l]Xu
V43TO
public void setSSiteURL(String value) eIH$"f;L
{ dN< ,%}R
sSiteURL = value; P;73Hr[E#
} \Wr,<Y
Nar>FR7ut
cMaOM}mS
public String getSFilePath() TN\|fzj
{ \w%@?Qik
return sFilePath; QOH<]~3J
} A|L'ih/
9gy(IRGq/
O(c@PJem
public void setSFilePath(String value) a7#?h%wf
{ iG#}`
sFilePath = value; %Ds+GM-
} H}/05e
5wv fF.v
Y]Vq\]m\
public String getSFileName() U<^F4*G
{ \vRd}
return sFileName; cG{L jt
} ?IF)+]
* ?]~ #
>P=Q #;v
public void setSFileName(String value) s2REt$.q
{ 3TS_-l
sFileName = value; g<wRN#B
} <CZgQ\Mt
_MuZ4tc
;j9\b9m
public int getNSplitter() E=$p^s
{ ) #+^ sAO
return nSplitter; jQ+sn/ROp
} ~Lz%.a;o
Gh\q^?}
&%mXYj3y5
public void setNSplitter(int nCount) Pw[g
{ Ef)yQ
nSplitter = nCount; U*)m',
} ]uQqn]+I!
} yN6>VD{F
&JP-O60
}H"kU2l
/* 1P(&J
**Utility.java g(|{')8?d
*/ t#i,1aHA
package NetFox; OLC{iD#
.@F]Pht
,|kDsR!
public class Utility { 4\M.6])_
cC'x6\a
?OlV"zK
public Utility() N!2Rl
{ DA&?e~L&H
o*rQP!8,oy
[*:6oo98'
} T~_/Vi
D BE4&
//线程睡眠 A:l@_*C..
public static void sleep(int nSecond) 5L,}e<S$
{ ^vilgg~
try{ -Go 7"j
Thread.sleep(nSecond); ig}A9j?]
} A][fLlpr
catch(Exception e) ::FS/Y]Fg
{ B=8Iu5m
e.printStackTrace (); 9o*,P,j'}
} qt%D'
} l 'DsZ9y@2
91>fqe
//日志 _BdE< !r
public static void log(String sMsg) VA*y|Q6
{ `K~AhlJUQ
System.err.println(sMsg); ~vlype3/EF
} 4lhw3,5
#jA[9gWI
om?-WJI
public static void log(int sMsg) B(xN Gs
{ `Qr%+OD
System.err.println(sMsg); NT@;N/I
} _=CZR7:O
} b4^`DHRu6
]BR,M4
{pM?5"MMJ
/* EdZ\1'&/9
**TestMethod.java fd-q3_f
*/ 5waKI?4F
package NetFox; rV08ad
x#Sqn#
UfS%71l.$
public class TestMethod { pPd#N'\*
a7N!B'y
e[hcJz!D
public TestMethod() 6G=j6gK%P
{ ///xx/weblogic60b2_win.exe g=I8@m
try{ Kq i4hK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _h}kp\sps
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M Y|w
SiteFileFetch fileFetch = new SiteFileFetch(bean); {nLjY|*
fileFetch.start(); U8 nH;}i
} 7jdb)l\p=
catch(Exception e){e.printStackTrace ();} 8#vc(04(
%2v4<icvq
/Q~i~B 2j-
} #8)*1?
_3ZYtmn.
iX)%Q
public static void main(String[] args) fkac_X$7
{ P#AW\d^"B
new TestMethod(); t.;LnrY
} thhwN A
} K5lmVF\$P
点击下载更多相关资料