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)); `NoCH[$!+
} I9:%@g]uYw
for(int i=0;i<nEndPos.length-1;i++) j>g9\i0O1
{ +9}' s{
nEndPos = nStartPos[i+1]; 0, "ZV}
} wJr/FE7c
nEndPos[nEndPos.length-1] = nFileLength; 2?pM5n
} R''Sfz>8
} X?_v+'G
P ]_Vz
L`JY4JM"
//启动子线程 ;lkf+,;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h?3f5G*&H
for(int i=0;i<nStartPos.length;i++) t.u{.P\Md\
{ x6~Fb~aP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9Iy[E,j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X~#@rg!"
nStartPos,nEndPos,i); `;T?9n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); td`wNy\
fileSplitterFetch.start(); *ig5Q(b*N
} ur`V{9g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9cbB[c_.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hAYQ6g$A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &,Uc>L%m
nEndPos = " + nFileLength); RDJ82{
// fileSplitterFetch[nPos.length-1].start(); IBF.&[[S
$&NbLjeS
>0ssza
//等待子线程结束 =1_jaDp
//int count = 0; gFgcxe6
//是否结束while循环 H.f9d.<W%
boolean breakWhile = false; bv_AJ4gS
1w6.
mURX I'JkX
while(!bStop) :hi$}xHa
{ 'fXer!L}
write_nPos(); F}\[eFf[
Utility.sleep(500); CVi<~7Am\
breakWhile = true; 79y'Ja+`j
I *1#
!fif8kf
for(int i=0;i<nStartPos.length;i++) Yr Preuh
{ R2'C s
if(!fileSplitterFetch.bDownOver) s@R3#"I
{ F'fM?!(
breakWhile = false; yFa&GxSq
break; %Ud.SJ3
} jWz|K
} &<m WA]cAL
if(breakWhile) RNsJ!or
break; Q9SPb6O2
pZW}^kg=
; \Y-
//count++; $K;_Wf
//if(count>4) xXl$Mp7
// siteStop(); eDvXU_yA
} {_+>"esc
T9,lblUQ
G`&'Bt{Z*
System.err.println("文件下载结束！"); NN?Bi=&9
} `,<>){c|
catch(Exception e){e.printStackTrace ();} !<JG&9ODP
} ^$3w&$K*
HP1X\h!Ke
h%4~0
//获得文件长度 =r=^bNO
public long getFileSize() hnlU,p&y3
{ #IcT @(
int nFileLength = -1; s#4))yUR6Z
try{ )3d:S*ly
URL url = new URL(siteInfoBean.getSSiteURL()); mvxc[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %@)U/G6s}
httpConnection.setRequestProperty("User-Agent","NetFox"); u9da]*\7y
k0Oc,P`'*
Va&KIHw
int responseCode=httpConnection.getResponseCode(); JT}dor
if(responseCode>=400) OqUE4.vIP
{ :z}~U3,JE
processErrorCode(responseCode); K.c6Rg
return -2; //-2 represent access is error Fvcq^uZ
} o%QhV6(F
,5%aP%
M}{n6T6B
String sHeader; !dYX2!lvT
P<g|y4h
_~(MA-l
for(int i=1;;i++) kY0g}o'<
{ AF07KA#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qt)7mf
//Utility.log(in.readLine()); t~udfOvY
sHeader=httpConnection.getHeaderFieldKey(i); ~%::r_hQ
if(sHeader!=null) :5n"N5Go
{ +$Ddd`J'
if(sHeader.equals("Content-Length")) 4l#T_y
{ SvCK;$:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w2RESpi
break; $Adp
} M?:f^
} ?Ix'2v
else (>kBmK1Aj
break; +;4AG::GN
} 'bQs_
} ;nHo%`Zt
catch(IOException e){e.printStackTrace ();} -6*OF.Ag`
catch(Exception e){e.printStackTrace ();} 8M5!5Jzv
$rV:&A
{&Gk.ODI7
Utility.log(nFileLength); +"fM &F]
*U5>j#,
p3'mJ3MA
return nFileLength; *]DJAF]
} XJV3oj
2Q;Y@%G
HtS1N}@
//保存下载信息（文件指针位置） rVIb'sa
private void write_nPos() /s-jR]#VA
{ 5O4&BxQ~}
try{ t8wz'[z
output = new DataOutputStream(new FileOutputStream(tmpFile)); -;DE&~p
output.writeInt(nStartPos.length); oVxV,oH(
for(int i=0;i<nStartPos.length;i++) tkUW)ScJ
{ y}H*p
// output.writeLong(nPos); ?geWR_Z
output.writeLong(fileSplitterFetch.nStartPos); ~,3v<A[5Vi
output.writeLong(fileSplitterFetch.nEndPos); a#~Z5>{
} y("0Xve
output.close(); <aQ; "O~
} M<|~MR
catch(IOException e){e.printStackTrace ();} 1\7"I-
catch(Exception e){e.printStackTrace ();} \!4ghev3
} J.+?*hcw
|4 d{X@`&
:[ZC-hc\
//读取保存的下载信息（文件指针位置） bC,M&<N
private void read_nPos() >?uH#%C5
{ uk>/Il
try{ K:Xrfn{s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x4 A TK
int nCount = input.readInt(); yz&q2
nStartPos = new long[nCount]; Qe=Q8cT
nEndPos = new long[nCount]; O(sFs1
for(int i=0;i<nStartPos.length;i++) (B~V:Yt
{ VHY<(4@
nStartPos = input.readLong(); vGMOXbq4&
nEndPos = input.readLong(); 8b#Yd
} vN6]6nUOiT
input.close(); ~Hs]}Xo
} w[$Wpae
catch(IOException e){e.printStackTrace ();} m6ZbYF-7W
catch(Exception e){e.printStackTrace ();} ZJJl944
} ,uD*FSp>
G5eLs
v!v0,?b*
private void processErrorCode(int nErrorCode) B}xo|:f!zj
{ @_weMz8}
System.err.println("Error Code : " + nErrorCode); yK2*~T,6@
} 7{/:,
:e9jK[)h0
8T1DcA*
//停止文件下载 A?Hjz%EcW
public void siteStop() U"R.!=v
{ RAkFgC~
bStop = true; p2_Zsq
for(int i=0;i<nStartPos.length;i++) 4~D>oNx4
fileSplitterFetch.splitterStop(); ?jM7C}
t>=y7n&q
1V9X(uP
} 2b&;Y/z
} (NWN&
//负责部分文件的抓取 e4_aKuA
**FileSplitterFetch.java `8b6 /
*/ SJuf`
package NetFox; Q24:G
(Vv[
}4ghT(C}$
import java.io.*; rp[oH=&
import java.net.*; UDi3dH=
rM?Dp2
m$UT4,Ol
public class FileSplitterFetch extends Thread { aFm]?75
d4eCBqx
es(LE/`e
String sURL; //File URL n^(yW
long nStartPos; //File Snippet Start Position Vv"wf;#
long nEndPos; //File Snippet End Position I4p= ?Ds
int nThreadID; //Thread's ID _e@qv;*
boolean bDownOver = false; //Downing is over F'_8pD7
boolean bStop = false; //Stop identical DlkKQ
FileAccessI fileAccessI = null; //File Access interface pvdZ>D-IU
HG6{`i
[/,6O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fvAV[9/-
{ )mO;l/,0
this.sURL = sURL; 21EUP6}8j
this.nStartPos = nStart; pnw4QQ9
this.nEndPos = nEnd; S^"e5n2
nThreadID = id; z00:59M4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GSb)|mj
} =FJ9wiL
>-o:> 5
cz~FWk
public void run() !?M_%fNE
{ M&T/vByTn_
while(nStartPos < nEndPos && !bStop) d/zX%
{ 8BH)jna`Qo
Leick6
Wn#JYp
try{ v})Ti190
URL url = new URL(sURL); a7d-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R;,HtN
httpConnection.setRequestProperty("User-Agent","NetFox"); K?m:.ZM
String sProperty = "bytes="+nStartPos+"-"; kb\v}gfiD/
httpConnection.setRequestProperty("RANGE",sProperty); |.8=gS5
Utility.log(sProperty); dw}3B8]
|]3);^0
Ln%_8yth
InputStream input = httpConnection.getInputStream(); 10a*7 L
//logResponseHead(httpConnection); @Lv_\^2/}
}$c($
S_;:iC]B
byte[] b = new byte[1024]; pXlBKJmW
int nRead; `i^1U O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "J:NW_U
{ \$|UFx
nStartPos += fileAccessI.write(b,0,nRead); ~:b~f]lO
//if(nThreadID == 1) nt`l6b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RSeezP6#
} H 6<@
uvM88#
`B0*/ml
Utility.log("Thread " + nThreadID + " is over!"); DL!s)5!M
bDownOver = true; &-Y:4.BXZ
//nPos = fileAccessI.write (b,0,nRead); 07Cuoqt2
} zate%y
catch(Exception e){e.printStackTrace ();} zO]dQ$r\Z
} x=+I8Q4:
} K'/x9.'%
F5q1VEe
OHvzK8
//打印回应的头信息 ?0&>?-?
public void logResponseHead(HttpURLConnection con) rzj'!~>U
{ kYa' ] m
for(int i=1;;i++) HliY
{ =gyK*F(RK
String header=con.getHeaderFieldKey(i); 5h7DVr!
if(header!=null) bu5)~|?{t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #7"5Y_0-
Utility.log(header+" : "+con.getHeaderField(header)); ] CE2/6Ph
else sgsMlZ3/
break; <W^~Y31:0
} KePHn:c
} 0].5[Jo
'Em($A(
UzwIV{
public void splitterStop() )U`kU`+'
{ Tj+WO6#V
bStop = true; 5X-{|r3q
} n_2LkW<?
4rdrl
#!@ ]%4
} ]qRz!D%@^
9:~^KQ{?
o>%W7@Pr
/* 86VuPV-
**FileAccess.java k_`S[
*//文件访问(定位，写) o#b9M4O
package NetFox; y +vcBuX
import java.io.*; \bE~iz3b9
svgi!=
Wd<}|?R
public class FileAccessI implements Serializable{ 9V!K._Cb
,%<77LE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M#|xj <p
RandomAccessFile oSavedFile; _<Tz1>j=
long nPos; Rznr9L
vM8]fSc
5?"ZM'4
public FileAccessI() throws IOException |u=57II#xK
{ jqmP^ZS
this("",0); ?yh.*,dgi
} d|lzkY~
?-i&6i6Y
LYv2ll`XP
public FileAccessI(String sName,long nPos) throws IOException kXRD_B5&
{ *i90[3l
oSavedFile = new RandomAccessFile(sName,"rw"); JH9CN
this.nPos = nPos; )63w&
oSavedFile.seek(nPos); dksnW!
} ar%Rr"
$^F2
y.OUn'^d4
public synchronized int write(byte[] b,int nStart,int nLen) $dVjxo
{ C%h_!z":
int n = -1; <#i'3TUR
try{ ymu#u
oSavedFile.write(b,nStart,nLen); p};<l@
n = nLen; W'yICt(#G
} Fx2&ji6u
catch(IOException e) 3f x!\
{ 6A<aelE*i
e.printStackTrace (); ~C3-E %h@Z
} K[Kc'6G
>d|W>|8e
b9Nw98`
return n; s RB8 jY
} EO^0sF<
kS>j!U(%d
Z~<V>b
} :mL.Y em*'
IAQ=d4V&
M_DkjuR
/* (;0]V+-
**SiteInfoBean.java -)/>qFj)
*/ iZF{9@
package NetFox; w@R-@ G
W%x#ps5%
/V~(!S>
public class SiteInfoBean { Fej$`2mRH
z Ey&%Ok
9i@*\Ada
private String sSiteURL; //Site's URL |tkmO:
private String sFilePath; //Saved File's Path ,;g:qe3D$
private String sFileName; //Saved File's Name b $!l*r
private int nSplitter; //Count of Splited Downloading File a+d|9y/k
Uz6B\-(0p
]|oqJ2P
public SiteInfoBean() u Wtp2]A
{//nSplitter的缺省值为5 l }[ 4
//default value of nSplitter is 5 v~SN2,h
this("","","",5); . x$` i
} Iq9+
#i?TCO
p O.8>C%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;6Z?O_zp4
{ SJfsFi?n
sSiteURL= sURL; -M:.D3,L
sFilePath = sPath; ZWv$K0agu
sFileName = sName; 1=>$c
this.nSplitter = nSpiltter; UA^E^$f:
7G(X:!
Hmz[pTQ|87
} Pj$a$C`Z
fw5AZvE6$
s<{c?4T
public String getSSiteURL() &,+ZNA`P
{ 6 J#C
return sSiteURL; yq2Bz7P
} Nt)9-\T
D6D*RTi4
9Rpj&0Is
public void setSSiteURL(String value) m@~HHwj
{ 1FuChd
sSiteURL = value; CBc}N(9
} 8w$cj'
d7@ N~<n
PO#FtG
public String getSFilePath() FU<rE&X2:
{ }k%>%xQ.
return sFilePath; }rN"H4)
} _=rXaTp
d 1z
Ofn:<d
public void setSFilePath(String value) L^22,B 0
{ p47~vgJN
sFilePath = value; $>+-=XMVB
} ;9rQN3J$gn
k[][Md2Vh
`g#\ Ws
public String getSFileName() E:7vm@+
{ g wk\[I`;
return sFileName; *J6qL! ["
} V[%r5!83H
0pu'K)Rb
:]x)lP(3E
public void setSFileName(String value) dX<UruPA
{ ~{HA!C#
sFileName = value; r J&1[=s
} ='s2S5#1
{KR/TQ?A
Z-WWp#b
public int getNSplitter() q,2 @X~T
{ P9c1NX\-
return nSplitter; iGR(
} bf3)^ 49}
4>(?R[:p)
#df Aqg'
public void setNSplitter(int nCount) M 3^p,[9r#
{ g?`w)O7v
nSplitter = nCount; !0cfz5t
} Kl^Yq
} m^`X|xK-
b*,R9
Ros5]5=dP
/* :yv! x
**Utility.java JjM^\LwKkL
*/ Drg'RR><
package NetFox; W2REwUps
p_qH7W
]TGJ|X
public class Utility { :D&QGw(n
^ K/B[8
`W"-jz5#=
public Utility() UF}fmDi
{ WS;3a}u
8z@A/$T
,2u]rLxx;
} y:1?~R
qoOHWh&
//线程睡眠 Yd]f}5F
public static void sleep(int nSecond) v%_sCg
{ sH6srwI
try{ 2t_E\W7w+
Thread.sleep(nSecond); MEg|AhP
} 9~a_^m/
catch(Exception e) ~]N% {;F}
{ 2-2'c?%
e.printStackTrace (); ? [=P
} Oyz=|[^,W
} dNIY`u
MECR0S9
//日志 7 0KZXgBy_
public static void log(String sMsg) rsrv1A=t?
{ .3$iOMCH
System.err.println(sMsg); jk)U~KGcg
} zS.7O'I<'
ZWYwVAo
d`^j\b>5(
public static void log(int sMsg) }P^{\SDX
{ LM0TSB?
System.err.println(sMsg); ucTkWqG
} -6#i~a]
} WMrK8e'
T_pE'U%[
1298&C@
/* F YcC2TM
**TestMethod.java ARslw*SJ
*/ K{HdqmxL.I
package NetFox; bvZmozbD
}Dk_gom_
L{aT"Of{X
public class TestMethod { }eBy p
3&_(D)+
g=a-zg9LX
public TestMethod() OG0ro(|dI
{ ///xx/weblogic60b2_win.exe 0M pX.0
try{ D7 A{*Tm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I9B B<~4o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bojm lVg
SiteFileFetch fileFetch = new SiteFileFetch(bean); r)ga{Nn,.
fileFetch.start(); sd Z=3)
} obUh+9K
catch(Exception e){e.printStackTrace ();} ?zxKk(J
8> Gp #T
M1VRc[ RRo
} s|dL.@0,L
AQ@A$
)p(XY34]
public static void main(String[] args) rY88xh^
{ julAN$2
new TestMethod(); {_PV~8u
} VAV@Qn
} IC7n;n9
点击下载更多相关资料