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)); Pa(^}n|
} .tkT<o-u<J
for(int i=0;i<nEndPos.length-1;i++) pnMEB,)
{ MzPzqm<
nEndPos = nStartPos[i+1]; hbU+Usx
} -yR.<KnL
nEndPos[nEndPos.length-1] = nFileLength; y'FS/=u>0
} [qdRUV'
} ~jK{ ,$:=
t(GR)&>.2
.R)PJc5^
//启动子线程 x??pBhJH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]DZE%
for(int i=0;i<nStartPos.length;i++) ~UyV<
{ ktK_e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~CtL9m3tO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <$6QDfa#
nStartPos,nEndPos,i); p7);uF^O%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~CVe yk< (
fileSplitterFetch.start(); nM\eDNK
} Ys -T0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,\X@~j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >a"Z\\dF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GQ*wc?f3
nEndPos = " + nFileLength); A;5n:Sd
// fileSplitterFetch[nPos.length-1].start(); ,B08i o-
SaC d0. h
7uT:b!^f[
//等待子线程结束 76>7=#m0u'
//int count = 0; [v$0[IuY,
//是否结束while循环 #BJG9DFP4`
boolean breakWhile = false; p>vn7;s2#
T_X6Ulp
mK[)mC _8
while(!bStop) Qhs/E`k4
{ 'D6T8B4
write_nPos(); ]V-W~r=
Utility.sleep(500); ^F2b hXE
breakWhile = true; 3k|oK'l
I<Ksi~*i
:gerQz4R8
for(int i=0;i<nStartPos.length;i++) kxp);
{ Z-8Yd6 4
if(!fileSplitterFetch.bDownOver) ?9! Z<H
{ \ W?R
breakWhile = false; rm4.aO~-F
break; vy_D>tp
} '7D,m H
} ^M%uV
if(breakWhile) %@;6^=
break; d}LRl"_n
w$H^q !(
9Q(+ZG=JkV
//count++; Na$Is'F&p
//if(count>4) uum;q-"
// siteStop(); F.-R r
} lE!a
\\{J'j>{f
@+'-ADX
System.err.println("文件下载结束！"); zrR`ecC(b
} w^Lta
catch(Exception e){e.printStackTrace ();} gzBy?r> r
} uHH/rMV
%7#-%{
CNQC^d\ h
//获得文件长度 xY+VyOUs
public long getFileSize() XW -2~?$
{ X/z6"*(|/
int nFileLength = -1; zUkN 0
try{ JoRT&rkd
URL url = new URL(siteInfoBean.getSSiteURL()); 1BAgtd$3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P~s$EJL*
httpConnection.setRequestProperty("User-Agent","NetFox"); D'L'#/hK
4J;-Dq
*<E]E?
int responseCode=httpConnection.getResponseCode(); 6'kS_Zu{<
if(responseCode>=400) Dfps gY)/?
{ 89n:)|rWq
processErrorCode(responseCode); 6(]tYcC
return -2; //-2 represent access is error 4|mD*o
} N;A@' tu8
d0aCY
}8@M@
String sHeader; N=5)fe%{4
hty0Rb[dH
V$"ujRp
for(int i=1;;i++) QCH}-q)
{ `(1K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fLSXPvm
//Utility.log(in.readLine()); ,*&G1|_6
sHeader=httpConnection.getHeaderFieldKey(i); R+nMy=I%8
if(sHeader!=null) fwrJ!j
{ "t({D
if(sHeader.equals("Content-Length")) 5DXR8mLoaJ
{ )I^2k4Cg"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Nc:({@I
break; ({-GOw46
} ! iptT(2
} %V1Z~HC
else yz-,)GB6
break; b B x?
} 4Sm]>%F':
} %r-V2)
catch(IOException e){e.printStackTrace ();} Yk'9U-.mc
catch(Exception e){e.printStackTrace ();} PzV@umC1#f
lz?;#U
iT;@bp
Utility.log(nFileLength); DHw&+MY
Py>{t4;S
!@x+q)2
return nFileLength; FuUD 61JHY
} S#-wl2z
%'xb%`t
wO:Sg=,
//保存下载信息（文件指针位置） U3izvM
private void write_nPos() S@}1t4Ls:
{ "]m+z)lWd
try{ EyI}{6~F
output = new DataOutputStream(new FileOutputStream(tmpFile)); kaxvPv1
output.writeInt(nStartPos.length); ?;wpd';c
for(int i=0;i<nStartPos.length;i++) bae\Zk%`^
{ }<>~sy
// output.writeLong(nPos); [U@*1
output.writeLong(fileSplitterFetch.nStartPos); "+z?x~rk
output.writeLong(fileSplitterFetch.nEndPos); K]qM~v<A
} R64!>o"nED
output.close(); T;diNfgg
} N7b1.]<
catch(IOException e){e.printStackTrace ();} OdQT2PA_
catch(Exception e){e.printStackTrace ();} Qd_Y\PzS
} .MVYB\6Q0
&n[~!%(
i\4hR?
//读取保存的下载信息（文件指针位置） KJ?y@Q
private void read_nPos() +B'8|5tPX
{ Z<#hS=eY
try{ 4<lQwV6=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W(25TbQ
int nCount = input.readInt(); 65oWD-
nStartPos = new long[nCount]; zOHypazOTq
nEndPos = new long[nCount]; v}sY|p"
for(int i=0;i<nStartPos.length;i++) Og2vGzD
{ p1D[YeF4
nStartPos = input.readLong(); K.%U
nEndPos = input.readLong(); '`|AI:L
} FVB;\'/
input.close(); fQ'.8'>T
} 0l=+$&D
catch(IOException e){e.printStackTrace ();} P_gYz!
catch(Exception e){e.printStackTrace ();} ?!=iu!J
} }C /]
x lsqj`=
4g}FB+[u
private void processErrorCode(int nErrorCode) ZkP{[^6d\
{ >#}2J[2HQ
System.err.println("Error Code : " + nErrorCode); dl5=q\1=
} ygSL
M wab!Ya
`e]6#iJ^
//停止文件下载 7l."b$U4yv
public void siteStop() !ph" mf$-
{ (>=7ng^
bStop = true; 2/36dGFH
for(int i=0;i<nStartPos.length;i++) 0Rz(|jlbS
fileSplitterFetch.splitterStop(); RGIoI]_
?( =p<TUw
)9B:wc"
} G~wFnl%
} 3Wcy)y>2Ap
//负责部分文件的抓取 8ZcU[8r
**FileSplitterFetch.java J9%@VZut
*/ <&pKc6+{
package NetFox; &[a Tw{2
D-IR!js ]
~:lKS;PRuK
import java.io.*; o5Y2vmz?9
import java.net.*; F52B~@.
_Mc>W0'5@
"BVdPSDBk
public class FileSplitterFetch extends Thread { xMs]Hs
/u`3VOn
TFR( 4W
String sURL; //File URL 9Bdt(}0A
long nStartPos; //File Snippet Start Position E2AW7f(/
long nEndPos; //File Snippet End Position Nt:8ogk/
int nThreadID; //Thread's ID kax\h
boolean bDownOver = false; //Downing is over W3&tJ8*3
boolean bStop = false; //Stop identical 'PlaMOy
FileAccessI fileAccessI = null; //File Access interface 4'Xgk8)
C;Ic
7OVbP%n)d2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I,ci >/+b
{ _2hXa!yO
this.sURL = sURL; k$Rnj`*^
this.nStartPos = nStart; y69J%/c ra
this.nEndPos = nEnd; P20|RvE
nThreadID = id; k_GP>b\"k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p|XAlia
} 8I+d)(:
g):]'
?Qqd "=k4
public void run() va|rO#.=
{ {13!vS%5
while(nStartPos < nEndPos && !bStop) MR'o{?{e`
{ n&-496H
*~z#.63oZ
>qn/<??
try{ 7ODaX.t->
URL url = new URL(sURL); -DO&_`kn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wH"kk4^
httpConnection.setRequestProperty("User-Agent","NetFox"); kII7z;<^`
String sProperty = "bytes="+nStartPos+"-"; RbQ <m!A
httpConnection.setRequestProperty("RANGE",sProperty); LH]CUfUrUE
Utility.log(sProperty); 49 }{R/:
C:\(~D*GS
$v}<'
InputStream input = httpConnection.getInputStream(); Ulqh@CE)
//logResponseHead(httpConnection); $_j1kx$
ujgLJ77
qJ8-9^E,L
byte[] b = new byte[1024]; 9 1P4:6
int nRead; R9r+kj_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `_ (~ Ud
{ > %*B`oqo
nStartPos += fileAccessI.write(b,0,nRead); VY'Q|[
//if(nThreadID == 1) ; !$m1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dEp/dd~(&
} ?RD *1
. p^xS6e{
A8?[6^%O|
Utility.log("Thread " + nThreadID + " is over!"); X)uDSI~
bDownOver = true; q42FPq
//nPos = fileAccessI.write (b,0,nRead); ua 8m;>R
} GVd48*
catch(Exception e){e.printStackTrace ();} Jp;k+"<q
} lr('k`KOQ
} LxJ6M/".
&1)xoZ'\
*M~.3$NN
//打印回应的头信息 FWPW/oC
public void logResponseHead(HttpURLConnection con) IlLn4Iw
{ <>4!XPo%J
for(int i=1;;i++) K%{ad1$c
{ "S(X[Y'
String header=con.getHeaderFieldKey(i); OM96`
if(header!=null) 'M'w,sID
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K5 vNhA
Utility.log(header+" : "+con.getHeaderField(header)); -S; &Q'Mt
else <fM>Yi5
break; 9Z!lmfnJ
} ^Gz{6@TY5
} &v#`t~
:d'65KMi
[}""@?
public void splitterStop() ,5-Zb3\
{ Q5E:|)G
bStop = true; BpT"~4oV5
} qj?2%mK`
Sa]Ek*
V 4qtaHf
} 5RA<Z.
o+)A'S
eihZp
/* kl{6]39
**FileAccess.java (zah890//
*//文件访问(定位，写) Uu2N9.5
package NetFox; ha'qIT3&
import java.io.*; 2uu[52H8d%
[V< 1_zqt
q]v,
public class FileAccessI implements Serializable{ aR(E7mXQ
&d 3HB=x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &|z544
RandomAccessFile oSavedFile; ag]*DsBt
long nPos; \8_V(lU
ABWb>EZ8
J'7 y
public FileAccessI() throws IOException +>E5X4JC
{ q0|ZoP
this("",0); z<QIuq
} SL*DK.
E*4t8
Rkv
public FileAccessI(String sName,long nPos) throws IOException >6K4b/.5w
{ m'.T2e.u
oSavedFile = new RandomAccessFile(sName,"rw"); 4]"w b5%
this.nPos = nPos; fu>Qi)@6a1
oSavedFile.seek(nPos); Fg@ ACv'@
} 3Wj,}
wG:$6
UT-ewXh
public synchronized int write(byte[] b,int nStart,int nLen) pYGYy'%A'
{ FH -p!4+]
int n = -1; n8FT<pUq
try{ 8dV=1O$/
oSavedFile.write(b,nStart,nLen); GEi MmH?
n = nLen; vU9~[I`^p
} }wkaQQh
catch(IOException e) -,@bA @&
{ =|#w.(3y
e.printStackTrace (); -y<x!61
} rIp'vy S\p
gN\*Y
s;>VeD)*)
return n; :xN8R^(
} ;Bnr='[
x?>!UqgkY
P7Z<0Dt\}
} o~}1oN
yr{5Rp05=
RR'(9QJ$
/* E~69^cd
**SiteInfoBean.java )ys=+Pz
*/ p9w%kM?
package NetFox; l)iv\j
%30T{n:
I W8.
public class SiteInfoBean { MyM+C}
7n<#y;wo
8+L7E-
private String sSiteURL; //Site's URL J2Y 3er
private String sFilePath; //Saved File's Path xLLC)~
private String sFileName; //Saved File's Name @C<d2f|8
private int nSplitter; //Count of Splited Downloading File &V FjHW
|Pj9ZG#
]#M/$?!]g2
public SiteInfoBean() ylT6h_z1[Y
{//nSplitter的缺省值为5 S].Ft/+H
//default value of nSplitter is 5 G$S1#F -
this("","","",5); cC'^T6
} l92!2$]b
8t--#sDy{0
s.bT[0Vl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @qpYDnJ:
{ JYl\<Z' {
sSiteURL= sURL; ,Os7T 1>
sFilePath = sPath; 9DY|Sa]#=
sFileName = sName; D'85VZEFyo
this.nSplitter = nSpiltter; oFwG+W/
widI s[ )
)fy<P;g
} ~t$mw,
_u`B3iG
3[,wMy"
public String getSSiteURL() K]%N-F>r
{ f>?^uSpWH
return sSiteURL; 4*YOFU}l
} L;4[ k;5
*EX$v4BX
1Q0%7zRirI
public void setSSiteURL(String value) ;7wwY$PBH
{ ;!^ +N
sSiteURL = value; ./';P<)
} (v|ixa
p"g1V7B
D8q3TyCj%
public String getSFilePath() Rd .U;>
{ J.*[gt%O|
return sFilePath; )A"ZV[eOoQ
} XX*'N+
8H&_,;
Y>(ZsHu
public void setSFilePath(String value) mL8A2>Gig
{ >~.Zr3P6kC
sFilePath = value; ?,D>+::
} .A )\F",X
0,;E.Py?.
],H1
public String getSFileName() NW}>pb9
{ #>MO]
return sFileName; h85(N
} FLi(#9
o(?VX`2"
782[yLyv
public void setSFileName(String value) `4$4bXrP'
{ HKq2Js
sFileName = value; 97['VOh0
} J(3gT}z-
T_(qN;_
*(@L+D0N
public int getNSplitter() i#CaKS
{ jc${.?m
return nSplitter; ._8xY$l$
} dM$N1DB{U+
bbfDt^
N |OMj%Uk
public void setNSplitter(int nCount) 7KvXTrN!9
{ CsJ)Z%4_
nSplitter = nCount; -d$8WSI8
} iSSc5ek4
} e{^:/WcYB
P-/XYZ]`
Z?!JV_K
/* {m?K2]](
**Utility.java K> c8r8!
*/ D[?k ,*
package NetFox; Vy?R/ Uu
ccHLL6F{
H1aV}KD
public class Utility { ?Zc/upd:$N
>reaIBT
BFzcoBu-
public Utility() yYxeNE"
{ 5`1(}
*/0vJz%<.M
Verbmeg&n
} m;;0 Cl
4jC4X*
//线程睡眠 >%PL_<Vbv
public static void sleep(int nSecond) [dSDg2]
{ [4K9|/J
try{ 7yq7a[Ra
Thread.sleep(nSecond); LUe>)eqw
} ~!a~C~_
catch(Exception e) 2b6? 9FX*
{ iBGSBSeL&
e.printStackTrace (); 3p?<iVE
} =j'J !M
} r`&2-]
h"RP>fZt
//日志 0?J|C6XM#4
public static void log(String sMsg) E<X{72fb>
{ RTgQ#<W8
System.err.println(sMsg); = )JVT$]w
} yr/]xc$
vp )}/&/
Y|GJph
public static void log(int sMsg) |Ak =-.
{ 4~m.#6MT
System.err.println(sMsg); cu.*4zs
} J1gEjd
} %2rHvF=
3<e(@W}n-M
.NzW@|
/* <WQ<<s@#pb
**TestMethod.java v -|P_O&z
*/ %-1BA*J`|
package NetFox; L5V'Sr
h a,=LV
yL.PGF1(
public class TestMethod { -H ac^4uF
U- *8%>Qp
W|r+J8
public TestMethod() ^LEmi1L
{ ///xx/weblogic60b2_win.exe P/C+L[X=
try{ ZuFVtW@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g "K#&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #Vn>ue+?
SiteFileFetch fileFetch = new SiteFileFetch(bean); Kc2OLz#
fileFetch.start(); $ +GFOO
} @^y?Bh9jQ
catch(Exception e){e.printStackTrace ();} }ZM*[j
EL 8N[]RF
[G'!`^V,
} [0tfY0
3gPD(r1g
$p}~,Kp/
public static void main(String[] args) $$bTd3N+
{ {LB }v;?l
new TestMethod(); k+7M|t.?4
} R$T[%AGZ.
} &k_wqV
点击下载更多相关资料