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)); =Htt'""DN
} y{M7kYWtHV
for(int i=0;i<nEndPos.length-1;i++) r1HG$^
{ Kb]}p
nEndPos = nStartPos[i+1]; ,~3rY,y-
} ^P,Pj z
nEndPos[nEndPos.length-1] = nFileLength; S/oD`
} ,x\qYz+7|
} %vO(.A+
`\@n&y[`7
:?UcD_F
//启动子线程 <oXBkCi0r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3[Q7'\
for(int i=0;i<nStartPos.length;i++) |cd"cx+
{ W$X/8K bn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fug4u?-n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X0L\Ewm
nStartPos,nEndPos,i); o_}?aI~H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6D]fDeH\
fileSplitterFetch.start(); 4M%|N
} BvvjaC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fTpG>*{p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r],%:imGr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yMdu Zmkc
nEndPos = " + nFileLength); 0to`=;JI
// fileSplitterFetch[nPos.length-1].start(); nP[Z6h
KC"S06
Rk5#5R n
//等待子线程结束 b~UWFX#U
//int count = 0; kB?/_a`]
//是否结束while循环 1>[#./@
boolean breakWhile = false; Ep(xlHTv
mxEe -q
.<vXj QE
while(!bStop) _#Hd2h
{ >NPK;Vu
write_nPos(); n><ad*|MX
Utility.sleep(500); k5>UAea_
breakWhile = true; +8xT}mX
<',k%:t
<b'*GBw$
for(int i=0;i<nStartPos.length;i++) ];CIo> b_(
{ eV%{XR?y
if(!fileSplitterFetch.bDownOver) auGK2i
{ BEax[=&W
breakWhile = false; |(l]Xr&O
break; r<kgYU`
} *A`ZcO=
} UU(Pg{DA6
if(breakWhile) db_Qt'>
break; }Tk:?U{
W;8A{3q%N0
eaO'|@;{~
//count++; iOfO+3'Z_U
//if(count>4) 5MG4S
// siteStop(); ` Ft-1eE
} ^O<v'\!z-
`oe=K{aX
//N="9)@
System.err.println("文件下载结束！"); <o9i;[+H-
} 3~R,)fO;
catch(Exception e){e.printStackTrace ();} /$clk=
} @H$8;CRM
J0vQqTaT
P(yLRc
//获得文件长度 Wgs6}1bg
public long getFileSize() sMAj?]hI$
{ Q7e4MKy7
int nFileLength = -1; 6p@[U>`
try{ ">!pos`<C
URL url = new URL(siteInfoBean.getSSiteURL()); uO]|YF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vn*K\,
httpConnection.setRequestProperty("User-Agent","NetFox"); J|hVD
`3jwjy|5
I++ Le%w
int responseCode=httpConnection.getResponseCode(); .Y2Hd$rs
if(responseCode>=400) NRG06M
{ q_^yma
processErrorCode(responseCode); $Tv~ *|a
return -2; //-2 represent access is error ,d*1|oUw
} A",}Ikh='`
oj.J;[-
&\ca ? #
String sHeader; ]#DCO8Vk
u(yN81
Ohj^Z&j
for(int i=1;;i++) Q}^Ip7T
{ 1p5'.~J+Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \:F$7 *Ne
//Utility.log(in.readLine()); fe<7D\Sp@
sHeader=httpConnection.getHeaderFieldKey(i); Y=|20Y\K
if(sHeader!=null) 2%fzRXhu%
{ F,)+9/S&
if(sHeader.equals("Content-Length")) [z\baL|
{ &,8Qe;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WI| -pzg
break; UrciCOQf
} Bx\ o8k
} ugXDnM[S%
else OcWKK!A
break; BUwL?
} 0\"#Xa+}8
} <uBRLe`)
catch(IOException e){e.printStackTrace ();} huA?*fat
catch(Exception e){e.printStackTrace ();} x6JV@wA&
A@_>9;
~9APc{"A
Utility.log(nFileLength); jP/Vqe%%8
z &P1C,n)
5m'AT]5Tn_
return nFileLength; d3\?:}o,
} %^E7Iqc
t zd#9 #
Z5oDj|&l}
//保存下载信息（文件指针位置） _#v"sGmN
private void write_nPos() l]D$QT3
{ 'bLP#TAzf
try{ j&/+/s9N
output = new DataOutputStream(new FileOutputStream(tmpFile)); {hOS0).(w7
output.writeInt(nStartPos.length); (Nz`w
for(int i=0;i<nStartPos.length;i++) "CC"J(&a
{ PfU\.[l$
// output.writeLong(nPos); I+twI&GS
output.writeLong(fileSplitterFetch.nStartPos); LHx ")H?,
output.writeLong(fileSplitterFetch.nEndPos); 2!}F+^8'P
} ,6MJW#~]
output.close(); Hmm0H6&u
} 'MX|=K!C
catch(IOException e){e.printStackTrace ();} !%}n9vr!}\
catch(Exception e){e.printStackTrace ();} )M"NMUuU"
} @,=pG
,J+L_S+B~
9XQE5^
//读取保存的下载信息（文件指针位置） W+u,[_
private void read_nPos() 6&'kN2
{ wXp:XZ:]T
try{ QsxvA;7%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wmVb0~[
int nCount = input.readInt(); Q[#8ErUY
nStartPos = new long[nCount]; &d6ud|
nEndPos = new long[nCount]; c\>I0HH;!
for(int i=0;i<nStartPos.length;i++) Z2g<"M
{ {Mb<onW
nStartPos = input.readLong(); ng|^Zm%
nEndPos = input.readLong(); @8`I!fZ
} ORP<?SG55u
input.close(); G na%|tUz|
} W;R6+@I[
catch(IOException e){e.printStackTrace ();} XNx$^I=
catch(Exception e){e.printStackTrace ();} WvF{`N
} `Rq|*:LV
"XV@OjrE
Q_fgpjEh/t
private void processErrorCode(int nErrorCode) 6Hb a@Q1`
{ z__t8yc3
System.err.println("Error Code : " + nErrorCode); PN9vg9'
} a%HNz_ro
b"#S92R+
s&o9LdL
//停止文件下载 I:oEt
public void siteStop() Ebj0 {ZL
{ w[l#0ZZ
bStop = true; rxMo7px@}I
for(int i=0;i<nStartPos.length;i++) =$bF[3D
fileSplitterFetch.splitterStop(); -le^ 5M7
kq(><T
F~E)w5?\O
} \hI?XnL#
} 'xai5X
//负责部分文件的抓取 ,0AS&xs$
**FileSplitterFetch.java S}h d,"I
*/ 3 ;F
package NetFox; F[O147&C
,)d`_AD+5
,KM%/;1Dm
import java.io.*; YwY?tOxBe
import java.net.*; 0e#PN@
/@ g 8MUq7
eJ<P
public class FileSplitterFetch extends Thread { ;c]O*\/
k0PwAt)65
"v wLj:
String sURL; //File URL $ eL-fg
long nStartPos; //File Snippet Start Position 1TA!9cz0Z
long nEndPos; //File Snippet End Position G8w@C
int nThreadID; //Thread's ID mYJ8O$
boolean bDownOver = false; //Downing is over uMGy-c
boolean bStop = false; //Stop identical jCtk3No
FileAccessI fileAccessI = null; //File Access interface 2P`./1L
,#;`f=aqTG
oF+yh!~mM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UJp'v_hN
{ D?S|]]Y!q
this.sURL = sURL; c8
this.nStartPos = nStart; &@|? %
this.nEndPos = nEnd; paN=I=:*M
nThreadID = id; &-^*D%9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (DvGA I
} ?(B}w*G~
"38<14V
!.V_?aYi8
public void run() gU&+^e >
{ gzVZPvTPE
while(nStartPos < nEndPos && !bStop) ,Iz9!i J"
{ n{<@-6
"#0P*3-c
\pK&gdw
try{ ?Q=(?yR0]
URL url = new URL(sURL); am.d^'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;}S_PnwC@
httpConnection.setRequestProperty("User-Agent","NetFox"); k 75 p
String sProperty = "bytes="+nStartPos+"-"; CpX[8>&osD
httpConnection.setRequestProperty("RANGE",sProperty); {P?DkUO}
Utility.log(sProperty); O{byMV{Ou
1#"wfiW
&u[F)|
InputStream input = httpConnection.getInputStream(); !E00I0W-h
//logResponseHead(httpConnection); />9`Mbg[G
|8k^jq
5lzbg
byte[] b = new byte[1024]; B3[X{n$px
int nRead; :$yOic}y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MU] F'6V
{ /i@.Xg@:
nStartPos += fileAccessI.write(b,0,nRead); .L#4#IO
//if(nThreadID == 1) W"#<r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RB""(<
} <T.R%Jys
<)O#Y76s
q\!"FDOl4
Utility.log("Thread " + nThreadID + " is over!"); vFLE%z{\o
bDownOver = true; #LR6wEk
//nPos = fileAccessI.write (b,0,nRead); .*YOyK3H
} }mZCQJ#`
catch(Exception e){e.printStackTrace ();} ^_G#JJ\@$
} &"tQpw5
} ny^uNIRPR
q |Pebe=
Mx93D
//打印回应的头信息 /#_[{lSr?
public void logResponseHead(HttpURLConnection con) l1 08.ao
{ G&wYV[Ln
for(int i=1;;i++) E)I&? <g
{ d9e~><bPJ
String header=con.getHeaderFieldKey(i); ~KGE(o4p
if(header!=null) "k [$euV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wx;%W"a
Utility.log(header+" : "+con.getHeaderField(header)); fIx|0,D&7L
else h;} fdk
break; ZZ!6O/M
} \KpJIHkBRy
} 't(#HBU
*n@rPr-
v/]xdP^Z
public void splitterStop() Y@ ;/Sf$Q
{ qB$QC
bStop = true; |4aU&OX
} 5f@&XwD9
9 s2z=^
FRPdfo37
} TDPQ+Kg_
G6Wa0Z
g;o5m}
/* TK>~)hc}
**FileAccess.java :N<o<qn
*//文件访问(定位，写) =-P<v2|e
package NetFox; ~$ ?85
import java.io.*; <Z~Nz>'r
Z>1yLt@ls
[["eK9}0
public class FileAccessI implements Serializable{ ]4*E:
e*D,2>o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \Z~@/OVc
RandomAccessFile oSavedFile; Pa|*Jcr
long nPos; 5?j#
Y3)*MqZlF
Lq@uwiq!
public FileAccessI() throws IOException Dg ~k"Ice
{ 65+2+p
this("",0); "x_G6JE4tv
} _a?x)3\v
G}WY0FC6
%3HF_DNOY=
public FileAccessI(String sName,long nPos) throws IOException $Zrc-tkV
{ YO@~y*,
oSavedFile = new RandomAccessFile(sName,"rw"); K"Irg.
this.nPos = nPos; G-o6~"J\
oSavedFile.seek(nPos); G&6`?1k
} /W}"/W9
K7qR
6k37RpgH
public synchronized int write(byte[] b,int nStart,int nLen) Y|-&=
{ 8k Sb92
int n = -1; /(s N@kt
try{ w);Bet
oSavedFile.write(b,nStart,nLen); vBY?3p,0p
n = nLen; FPE6H:'
} #xq|/JWs
catch(IOException e) 7.yCs[Z
{ hx~rq`{
e.printStackTrace (); J?&%fI
} 6LT.ng
bSTTr<W
z=rSb4"W
return n; >dDcm
} P!&yYR\
S*ie$}ZX
=}+xD|T
} WZbRR.TxO
U'}[:h~)
leXdxpc
/* 1l}fX}5%I;
**SiteInfoBean.java d=HD! e
*/ Y1DbBDk
package NetFox; B|AIl+y
-BrJ5]T>*
N;cSR\Ng
public class SiteInfoBean { 9J}^{AA
E,A9+OKxJ
(.$e@k=
private String sSiteURL; //Site's URL r,GgMk
private String sFilePath; //Saved File's Path [&p/7
private String sFileName; //Saved File's Name |L <
private int nSplitter; //Count of Splited Downloading File #J$z0%P
|A)a ='Ap
~\O,#j`_
public SiteInfoBean() T<0V ^B7
{//nSplitter的缺省值为5 > mP([]
//default value of nSplitter is 5 A(JgAV1{
this("","","",5); Qer}eg`R
} gp^xl>E
)Y=ti~?M(
}A<fCm7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OK:YnSk"
{ t1o_x}z4.
sSiteURL= sURL; 3`njQvI\
sFilePath = sPath; [5P1 pkZ
sFileName = sName; &:=[\Ws R
this.nSplitter = nSpiltter; //}KWz
.`h:1FP8
+L=a\8Ep
} pG$l
xHn "D@
g`H;~ w
public String getSSiteURL() RWGAxq`9f
{ 2&<&q J
return sSiteURL; 6?l|MU"Q.
} ~:UAL}b{\~
~=Fp0l)#
Rdy-6
public void setSSiteURL(String value) B,{Q[
{ [g lhru=+
sSiteURL = value; 3=^B &AB
} v*@R U
kE{-h'xADD
K=J">^uW
public String getSFilePath() 3TT?GgQ
{ fjy2\J!
return sFilePath; \'P79=AU
} u< 5{H='6
?Aky!43
ue!wo-|#G
public void setSFilePath(String value) Q~)A fa{
{ 'u%SI]*;>
sFilePath = value; '&iAPc4=
} ']>/$[!
xbze{9n"
:h<QM$P<
public String getSFileName() ju/#V}N
{ "l-b(8n
return sFileName; T:w%RF[v9
} 5GWC
[mG:PTK3
' "o2;J)7
public void setSFileName(String value) 24d{ol)
{ @Yzb6@g"
sFileName = value; y6Ea_v
} TZE;$:1vx>
+(o]E3
T=T1?@2C
public int getNSplitter() :>, m$XO
{ ap.L=vn
return nSplitter; BGL-lJrG
} \7tJ)[0aF
8FT@TUFb
YR0.m%U,
public void setNSplitter(int nCount) ]iH~1[
{ T|h'"3'
nSplitter = nCount; NAEAvXj
} |&0Cuwt
} sj%\lq
|6zx YuX
tD3v`Ke
/* P&9&/0r=_
**Utility.java K}Rq<zW
*/ $or8z2d1
package NetFox; OC_i,
0D^c4[Y'l
JReJlDu
public class Utility { 6^hCW`jG
s7na!A[
eih~ SBSH
public Utility() iKe68kx
{ A$XmO}+
Nmu=p~f}3`
\kVi&X=q:
} |j~{gfpSE
'n4 iW
//线程睡眠 cR/z;*wr7
public static void sleep(int nSecond) 5vqh09-FB
{ {x/)S*:Z
try{ kU[#. y=%p
Thread.sleep(nSecond); ~ZZJ/Cu
} 9|1J pb
catch(Exception e) IRB BLXv7\
{ ($*R>*6<x
e.printStackTrace (); ;\)N7SJ
} )E(9 R(
} WeRX~
gC\^"m
//日志 h(3ko An
public static void log(String sMsg) D;WQNlTU
{ y?yWM8
System.err.println(sMsg); @DA.$zn&
} =/L;}m)7
$VyH2+ jC
V[r1bF
public static void log(int sMsg) Pvu*Y0_p
{ CWS&f g%o{
System.err.println(sMsg); ca!DZ%y
} 4Q n5Mr@<
} 2g:V_%
)6 [d'2
#a=~a=c(^
/* Z2hIoCT
**TestMethod.java S|v")6
*/ (b>B6W\&
package NetFox; x#,nR]C
"qvJ-Y
W<s5rMx
public class TestMethod { <c$K3
Q=Y1kcTOn
UfAN)SE"
public TestMethod() Mg76v<mv<
{ ///xx/weblogic60b2_win.exe ?wYvBFRn7"
try{ K1*]6x,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M~t;&po
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5>*~1}0T
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3X A8\Mg
fileFetch.start(); ,CA3Q.y>|
} ]\Q9j7}37+
catch(Exception e){e.printStackTrace ();} %+e% RZ3
Or*e$uMIY
P{_Xg,Z
} |>L|7>J{<d
QvjOOc@k~n
y(uE
public static void main(String[] args) ej&ZE n
{ La#otuw+?
new TestMethod(); STY\c5
} :r,o-D
} f+iM_MI
点击下载更多相关资料