http断点续传简单实现（java)

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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)); W.u}Q@
} Gvw:h9v
for(int i=0;i<nEndPos.length-1;i++) eu|cQ^>
{ Y/_b~Ahn
nEndPos = nStartPos[i+1]; IGd]!
} BI-xo}KI
nEndPos[nEndPos.length-1] = nFileLength; @{!c [{x,T
} 'Nv*ePz
} J@c)SK%2h
k:0HsN!F9
\{[Gdj`
//启动子线程 <M|kOi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ca1A9fvo
for(int i=0;i<nStartPos.length;i++) AA$-Lx(UJk
{ RE(R5n28,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u%vq<|~-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PNn{Rt
nStartPos,nEndPos,i); BK8)'9/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e" f/
fileSplitterFetch.start(); ^H1B62_
} 8D U|j-I8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zg/ra1n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'J&$L c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P'6eK?
nEndPos = " + nFileLength); ?_9A`LC*
// fileSplitterFetch[nPos.length-1].start(); kN*,3)T;}
4c*?9r@
wQX,a;Br
//等待子线程结束 -*u7MFq_
//int count = 0; /=}w%-;/;
//是否结束while循环 L}1|R*b
boolean breakWhile = false; >>voLDDd
@exeHcW61
gZe(aGh
while(!bStop) *94<rlh{"
{ #B3P3\
write_nPos(); x_vaYUl)
Utility.sleep(500); 4jlUyAD
breakWhile = true; Vs)Pg\B?
#?Z>o16,u
((}T^
for(int i=0;i<nStartPos.length;i++) tN=B9bm3j
{ Wi Mi0?$.
if(!fileSplitterFetch.bDownOver) p#UrZKR
{ ?[}r& f
breakWhile = false; ~e5hfZv|w
break; e:E:"elr]
} c-L1 Bkw
} B6&;nU>;
if(breakWhile) Pvq74?an`
break; %o4ZD7@ '
Pwn3/+"%K
l.c*,9
//count++; >weY_%a
//if(count>4) |#);^z_
// siteStop(); P\B ]><!ep
} #MbkU])
F/FUKXxx
I5l5fx
System.err.println("文件下载结束！"); 'a`cK;X9F
} YQWGv,47\
catch(Exception e){e.printStackTrace ();} ab5 a>w6}
} XjL)WgQ{i
dBKL_'@@}
KErQCBeJ
//获得文件长度 d|!FI/
public long getFileSize() d7.}=E.L
{ r5kKNyJ
int nFileLength = -1; x w8 e
try{ S:IhJQ4K
URL url = new URL(siteInfoBean.getSSiteURL()); cRm+?/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3xSt -MA
httpConnection.setRequestProperty("User-Agent","NetFox"); -\OvOkr
fz[o;GTc
kQ5mIJ9(
int responseCode=httpConnection.getResponseCode(); 5\MCk"R!
if(responseCode>=400) E-Nc|A
{ kcg{z8cd'r
processErrorCode(responseCode); zO BLF|L=
return -2; //-2 represent access is error e5/f%4YX
} `52+.*J+%
+yvtd]D$2W
P;7JK=~k
String sHeader; q#RUL!WF7U
lxIoP
s9R#rwIc
for(int i=1;;i++) Id6H~;
{ OIpkXM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Jm2|WKH
//Utility.log(in.readLine()); jlvh'y`
sHeader=httpConnection.getHeaderFieldKey(i); ' U]\]Wp
if(sHeader!=null) @]v}&j7
{ (gY3?&Ok*
if(sHeader.equals("Content-Length")) ~:`5Y"Av:
{ EDQKbTaPt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !6Sr*a*5
break; F xek#
} |$*1!pL-QP
} or~2r8
else LhN?j5XqM
break; 3q'["SS
} *$K_Tii
} b.mcP@
catch(IOException e){e.printStackTrace ();} 87; E#2
catch(Exception e){e.printStackTrace ();} 2a=3->D&
usj:I`>
RLy(Wz3%
Utility.log(nFileLength); -|0nZ
`1}WQS
aQjs5RbP~
return nFileLength; CD}::7$
} 6_Ps*Ed
,%)O/{p_
&8p]yo2zO
//保存下载信息（文件指针位置） _yH{LUIj
private void write_nPos() =E6ND8l@2
{ +,7nsWV
try{ yx0wR
output = new DataOutputStream(new FileOutputStream(tmpFile)); O;zq(/,-l
output.writeInt(nStartPos.length); I5#KLZVg
for(int i=0;i<nStartPos.length;i++) .|\}]O`
{ cQg:yoF
// output.writeLong(nPos); 'q3<R%^Q
output.writeLong(fileSplitterFetch.nStartPos); _C`&(?}
output.writeLong(fileSplitterFetch.nEndPos); z$64Ep#
} WP5cC@x
output.close(); JVfSmxy.
} J,iS<lV_
catch(IOException e){e.printStackTrace ();} Fru&-T[
catch(Exception e){e.printStackTrace ();} ?3[Gh9g`
} <}uhKp>*
,7HlYPec
-!o*A>N
//读取保存的下载信息（文件指针位置） N>pTl$\4
private void read_nPos() (G1KMy
{ 8jBrD1
try{ @:,B /B;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f.yvKi.Cm
int nCount = input.readInt(); k^VL{z:EWB
nStartPos = new long[nCount]; ,> Ya%;h2k
nEndPos = new long[nCount]; zR@4Z>6
for(int i=0;i<nStartPos.length;i++) pc/x&VY%
{ \#50; 8VJ
nStartPos = input.readLong(); xG_LEk( zD
nEndPos = input.readLong(); [TX1\*W
} $6[%NQp
input.close(); 91f{qq=#J{
} 4{PN9i E
catch(IOException e){e.printStackTrace ();} O)N$nBnp
catch(Exception e){e.printStackTrace ();} ,xSNTOJ
} "A(D}~i
PiwMl)E|!
53X i)
private void processErrorCode(int nErrorCode) u~O9"-m !V
{ 9%#u,I
System.err.println("Error Code : " + nErrorCode); Rb/|ae
} ^X]rFY1
NqlU?
_xWX/1DY
//停止文件下载 Ez1-Nx
public void siteStop() ylGT9G19
{ 3VZ}5
bStop = true; 14~#k%zO(
for(int i=0;i<nStartPos.length;i++) j.]ln}b/'+
fileSplitterFetch.splitterStop(); AU$<W"%R
tDC?St1
at|.Q*&a#
} ;S_Imf0$v
} iv!;gMco
//负责部分文件的抓取 O#_\@f#[
**FileSplitterFetch.java c9ye[81
*/ ge#0Q L0K
package NetFox; 5)c B\N1u
"F[e~S#V*
#x+7-hi
import java.io.*; >b7Yk)[%
import java.net.*; xe4`D>LUo
9^?2{aP%
SuR+Vv
public class FileSplitterFetch extends Thread { d53Eu`QW?
+@^FUt=tq
: uxJGx
String sURL; //File URL sC'PtFK8z
long nStartPos; //File Snippet Start Position +xL' LCx
long nEndPos; //File Snippet End Position u<U8LR=)V5
int nThreadID; //Thread's ID !#Pr'm/,mu
boolean bDownOver = false; //Downing is over Cl8S_Bz
boolean bStop = false; //Stop identical o$p] p9
FileAccessI fileAccessI = null; //File Access interface +;Pkpuu
*b4W+E
Z!+n/ D-1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /B 53Z[yL
{ 1rIL[(r4
this.sURL = sURL; GU0[K#%
this.nStartPos = nStart; w-"tA`F4
this.nEndPos = nEnd; Q<Q?#v7NX
nThreadID = id; 0 wjL=]X1e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'u#c_m!9
} 5oe{i/#di
F2>W{-H+
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public void run() D!DL6l`
{ P(bds
while(nStartPos < nEndPos && !bStop) 84_Y+_9
{ \IhHbcF`d
;uho.)%N`F
-]Ny-[P
try{ yJ:rry
URL url = new URL(sURL); :-Wh'H(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HPY;UN
httpConnection.setRequestProperty("User-Agent","NetFox"); gXj3=N(l
String sProperty = "bytes="+nStartPos+"-"; j.yh>"de
httpConnection.setRequestProperty("RANGE",sProperty); 84lT# ^q
Utility.log(sProperty); &s{d r
U6F7dT
3>v-,S+
InputStream input = httpConnection.getInputStream(); y&A&d-
//logResponseHead(httpConnection); {(IHHA>
3V]08
mhMTn*9
byte[] b = new byte[1024]; Doe:m#aNj
int nRead; pK"iTc#\X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @x^/X8c(p
{ ro+8d
nStartPos += fileAccessI.write(b,0,nRead); U UhlKV|5
//if(nThreadID == 1) D/ tCB-+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |&MOus#v
} z.!u<hy(
b5#Jo2C`AJ
lot;d3}
Utility.log("Thread " + nThreadID + " is over!"); YIs_.CTi
bDownOver = true; 3F8KF`*
//nPos = fileAccessI.write (b,0,nRead); l>T]Y
} v"*c\,
catch(Exception e){e.printStackTrace ();} Byh!Snoe
} OWp`Wat
} E&ReQgBft
-nZDFC8y$
v\g1w&PN
//打印回应的头信息 EeQ2\'t
public void logResponseHead(HttpURLConnection con) w0O(>
{ _&M^}||UH
for(int i=1;;i++) yBCLS550
{ UJuz
String header=con.getHeaderFieldKey(i); ezA&cZ5
if(header!=null) ,b<m],p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mYqLqezAA
Utility.log(header+" : "+con.getHeaderField(header)); A>frf[fAW
else *|^|| bd
break; U1D;O}z~
} Z-L}"~
} ~ %Ij5PD
Z6nQW53-
y:Agmr,S
public void splitterStop() Ih[k{p
{ ltv~Kh
bStop = true; ~i]4~bkH2
} It]GlxMX
^}UFtL i
j>5X^Jd
} %v0;1m
";upu
w3;T]R*
/* |+Xh ^E
**FileAccess.java hbSKlb0d
*//文件访问(定位，写) Of-8n-
package NetFox; 94?/Rhs5
import java.io.*; h(i_'P?
8g?2( MT;
Lie= DD
public class FileAccessI implements Serializable{ `,Fc271`
TpYdIt9#>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T#KVN{O
RandomAccessFile oSavedFile; ~ymSsoD^
long nPos; J&L#^f*d
55Xfu/hQ
Xif>ZL?aXb
public FileAccessI() throws IOException 3x=NSe|f
{ L% T%6p_
this("",0); [KMS/'; ]
} `j'gt&
id)J;!^;J
keJ-ohv)
public FileAccessI(String sName,long nPos) throws IOException eI@G B
{ P!!:p2fo
oSavedFile = new RandomAccessFile(sName,"rw"); JHuA}f{2&
this.nPos = nPos; [4-u{Tu
oSavedFile.seek(nPos); JmuoYlf|
} g@m__
@2eH;?uO
+D?Re%HI
public synchronized int write(byte[] b,int nStart,int nLen) 6?-,@e
{ `a8&7J(
int n = -1; 91ec^g
try{ 1]aya(
oSavedFile.write(b,nStart,nLen); ,w,)n^
n = nLen; +$R%Vbd
} _@Y17L.
catch(IOException e) LbnF8tj}h
{ 'EB5#
e.printStackTrace (); 0{u#{_
} ^t[br6G
2\#~%D>[
xw3A|Aj?r
return n; XeozRfk%J|
} 787}s`,}
{ /Gm|*e{
W|6.gN]
} lAAPV
^3nB2G.ax
nz`"f,
/* Y|<1|wGG
**SiteInfoBean.java ROj=XM:+
*/ o2^?D`Jr
package NetFox; F5<GGEQb
_p| KaT``
'~76Y9mv
public class SiteInfoBean { [jF\"#A
$I a-go2W
^Y^5 @x=
private String sSiteURL; //Site's URL NTSKmCvQG
private String sFilePath; //Saved File's Path HgRfMiC
private String sFileName; //Saved File's Name ]2xoeNF/W{
private int nSplitter; //Count of Splited Downloading File {N0ky=ud
[,qb) &_
DO? bJ01
public SiteInfoBean() =e]Wt/AQ
{//nSplitter的缺省值为5 1F?ylZ|~
//default value of nSplitter is 5 8;P_KRaE
this("","","",5); _1?Fyu&<5
} mGUl/.;yp-
r<.*:]L
=_d-MJy~6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C5oIl_t
{ :w4I+*]
sSiteURL= sURL; z|G 39
sFilePath = sPath; .w)T2(
sFileName = sName; Jm}zit:o
this.nSplitter = nSpiltter; @_Ly^' "
Oxf,2r
h_h6@/1l
} 0"M0tA#
^i~'aq
1H,hw
public String getSSiteURL() 2n5{H fpY
{ U_e e3KKA
return sSiteURL; p%*!]JRS
} 7 m!e\x8
_Y,d|!B#L
d:=:l?
public void setSSiteURL(String value) 2BIOA#@t
{ veGRwir
sSiteURL = value; ]ipltR7k
} V %Rz(a+c
pi?U|&.1z
-\=kd {*B
public String getSFilePath() Gnmxp%&}P|
{ Yim`3>#t
return sFilePath; eVy\)dCsU
} ]#oqum@Yf1
(#k2S-5
^7% KS
public void setSFilePath(String value) B\Y!5$
{ S#, E)h/
sFilePath = value; f<G:}I
} )haHI)xR
w`OHNwXh#I
oGi{d5
public String getSFileName() 3:WXrOl
{ qbe9 CF'@_
return sFileName; c6)q(zz
} :S |)
K.jm>]'z4;
ceqYyVy
public void setSFileName(String value) K-*q3oh G
{ rhe;j//`
sFileName = value; c\pPwG
} H@xIAL
c/E6}OWA
VR9C< tMSi
public int getNSplitter() ua vv
{ }nJG<rY
return nSplitter; &D~70N\L
} ,*@6NK,.
p#dpDjh
,M&[c|
public void setNSplitter(int nCount) tJ9i{TS
{ r-a/vx#
nSplitter = nCount; j/xL+Y(=
} !(<Yc5
} <C_FI` wk
#wZ:E,R
K)"cwk-
/* hol54)7$3:
**Utility.java Ng3MfbFG
*/ UN}jpu<h
package NetFox; xdH*[
Pc4FEH/
glppb$oB\
public class Utility { G&Sp }
RT)*H>|
T+[N-"N
public Utility() j@b4)t
{ *:}NS8hP
O5Xu(q5+
{^#62Y
} x1kb]0s<-
eOQUy+
//线程睡眠 kEE8cW3
public static void sleep(int nSecond) \}e1\MiZ
{ dEp?jJP$;
try{ +)fl9>Mb
Thread.sleep(nSecond); !:mo2zA
} 0VB~4NNR
catch(Exception e) rsR0V+(W
{ !s]LWCX+|
e.printStackTrace (); QMfa~TH#p
} j[h4F"`-
} r^k:$wJbRK
5Qik{cWxBq
//日志 GiN\nu<!
public static void log(String sMsg) ccJ@jpXI
{ #U NTD4
System.err.println(sMsg); TK;*:K8oe
} <"@~
Nd~?kZZu
%Y` @>P'
public static void log(int sMsg) %jY/jp=R
{ !z;a>[T'
System.err.println(sMsg); i(JBBE"
} _e=R[
} tw]RH(g+#
cRX0i;zag
|.Bb Pfe8f
/* oO|zRK1;/
**TestMethod.java gaC^<\J
*/ u><gmp&
package NetFox; ,iU ]zN//
HZdmL-1Z^+
m[C-/f^u|
public class TestMethod { */n)_
+!V*{<K
/)xG%J7H
public TestMethod() [BHf>
{ ///xx/weblogic60b2_win.exe Mrp'wF D
try{ 8Z!+1b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k|,pj^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @#}9?>UV
SiteFileFetch fileFetch = new SiteFileFetch(bean); FG-w7a2mn
fileFetch.start(); Nf>1`eP
} 02} &h
catch(Exception e){e.printStackTrace ();} A}sb2P
$L.0$-je4
m El*{]
} IEdC _6G
|*7uF<ink6
a8-2:8Su
public static void main(String[] args) t#~r'5va
{ !Ljs9 =UF
new TestMethod(); #:Di1I9<O7
} |$":7)eH!
} AU}P`fT!
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