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)); vzX%x ul
} h 8<s(WR
for(int i=0;i<nEndPos.length-1;i++) !w1acmo<_
{ y3XR:d1cg
nEndPos = nStartPos[i+1]; }|UTwjquBD
} u+lNcyp"MW
nEndPos[nEndPos.length-1] = nFileLength; /np05XhEa
} G^ShN45
} :3N6Ej
V~#8lu7;
Tuz~T _M
//启动子线程 f_|pl^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ajCe&+
for(int i=0;i<nStartPos.length;i++) Z-j?N{3&
{ fQU5'wGp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %45*DT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %E8HLTEvl
nStartPos,nEndPos,i); ~@#s<a,%;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j'x@P+A
fileSplitterFetch.start(); -!lSk?l
} I*z|_}$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8\F|{vt#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i);BTwW)#]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uS<og P
nEndPos = " + nFileLength); qWU59:d^{
// fileSplitterFetch[nPos.length-1].start(); -G[TlH06
lT?Vt`==~M
:]JMsa6
//等待子线程结束 )Vz=:.D
//int count = 0; vs^)=
//是否结束while循环 g#Z7ReMw
boolean breakWhile = false; =qvn?I^/
4`Cgz#v {
zr ~4@JTS
while(!bStop) !eHQe7_
{ 5d;(D i5z
write_nPos(); L)i6UAo
Utility.sleep(500); 9=J 3T66U
breakWhile = true; rR4?*90vjj
/2Z7
a|5<L
for(int i=0;i<nStartPos.length;i++) O]XgA0]
{ y*Gq VA[
if(!fileSplitterFetch.bDownOver) ^V~^[Yp
{ R5i xG9
breakWhile = false; d};[^q6X
break; 9ec>#Vxx
} z57q|
} t*`G@Nj
if(breakWhile) )EK\3q
break; UGxF}Q
%CZGV7JdA
ai<K6)
//count++; e6>[ZC
//if(count>4) QFB2,k6jN
// siteStop(); DW>O]\I
} CHi t{ @9
"yK)9F[9Mo
?pdN!zOeL
System.err.println("文件下载结束！"); bZ#KfR
} th{ie2$
catch(Exception e){e.printStackTrace ();} E9w"?_A)
} cm8co
g,G{%dGsk
V`0Y p
//获得文件长度 iA|n\a~ny,
public long getFileSize() hh$i1n
{ NxzAlu
int nFileLength = -1; </B:Zjn
try{ %EYh*g{G
URL url = new URL(siteInfoBean.getSSiteURL()); gW?Hd/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tiy#b8
httpConnection.setRequestProperty("User-Agent","NetFox"); o4^#W;%w
BC85#sbl
q&&uX-ez5W
int responseCode=httpConnection.getResponseCode(); ,g1~4,hqQ
if(responseCode>=400) VVEJE$
{ ]M 2n%9
processErrorCode(responseCode); #<@_mbQ@|K
return -2; //-2 represent access is error UhXVeGO
} S"fqE%
R2qz>kyyB
uF{l`|b'
String sHeader; Pz|}[Cx-
wH\ K'/
e +jp,>(v
for(int i=1;;i++) RDeI l&
{ ~iIFe+6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K#N5S]2yb
//Utility.log(in.readLine()); -%Jm-^F I
sHeader=httpConnection.getHeaderFieldKey(i); 5! ]T%.rM
if(sHeader!=null) P V9q=
{ 8}X>u2t
if(sHeader.equals("Content-Length")) c],Zw
{ AHT(Z~C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b%X<'8z9Z
break; R0yp9icS
} _$mS=G(
} PKev)M;C+
else k#2b3}(,
break; Qqd+=mgc
} #UnGU,J
} 5r0Sl89J
catch(IOException e){e.printStackTrace ();} !MOcF5M
catch(Exception e){e.printStackTrace ();} Q@s G6iz
{\VmNnw
/AIFgsaY
Utility.log(nFileLength); ?U,XyxN
yn2k!2]&T<
}cIj1:
return nFileLength; t?p>L*
} v){X&HbP
r2&/Ii+
W,%qL6qV
//保存下载信息（文件指针位置） zB"y^g
private void write_nPos() 3P*"$fH
{ rY"EW"y
try{ 'l1cuAP!+
output = new DataOutputStream(new FileOutputStream(tmpFile)); InG<B,/W?
output.writeInt(nStartPos.length); ^Uldyv/
for(int i=0;i<nStartPos.length;i++) 6a6N$v"
{ ?YM0VB,y
// output.writeLong(nPos); g:>dF#
output.writeLong(fileSplitterFetch.nStartPos); K14{c1
output.writeLong(fileSplitterFetch.nEndPos); 602=qb
} 5?TjuGc
output.close(); %Gjjl*`E
} ks8xxY
catch(IOException e){e.printStackTrace ();} F'55BY*!
catch(Exception e){e.printStackTrace ();} ([hd
} |H8UT SX+
r+nhm"9
=V^8RlBi
//读取保存的下载信息（文件指针位置） 0[s<!k9=
private void read_nPos() D|8h^*Ya
{ cV* 0+5
try{ :5zO!~\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K st2.Yy
int nCount = input.readInt(); k= 9a/M u
nStartPos = new long[nCount]; ,oj)`?Vh
nEndPos = new long[nCount]; =1j`VJU9
for(int i=0;i<nStartPos.length;i++) jE$]Z(Ab
{ =l$qwcfbo
nStartPos = input.readLong(); (<yQA. M
nEndPos = input.readLong(); o&E2ds3
} vFGVz
input.close(); gjy:o5{vA*
} q%FXox~b
catch(IOException e){e.printStackTrace ();} 7=4V1FS6i
catch(Exception e){e.printStackTrace ();} x{{ZV]
} ;7yt,b5&C
B=2f-o
+'D #VG
private void processErrorCode(int nErrorCode) "\kr;X'
{ ptpu u=3"
System.err.println("Error Code : " + nErrorCode); SG3qNM: g
} EJO6k1
bhT:MW!
nIqmora
//停止文件下载 Jz)c|8U
public void siteStop() `L"{sW6S
{ ZQDw|*a@
bStop = true; mr`EcO0
for(int i=0;i<nStartPos.length;i++) zC$(/nZ
fileSplitterFetch.splitterStop(); N:rnH:g+:
xwrleB
r/6h}
} u}KEH@yv
} >l!DWi6
//负责部分文件的抓取 nL* SNQ_
**FileSplitterFetch.java ,m.IhnCV\
*/ Edav}z
package NetFox; !CuLXuM
"ZFK-jn/
YS&Q4nv-
import java.io.*; ^1+&)6s7V
import java.net.*; s&WHKCb
9@z"~H
TWJ%? /d
public class FileSplitterFetch extends Thread { .cm$*>LW:x
#3Jn_Y%P.
Hh.l,Z7i7D
String sURL; //File URL V s1Z$HS`
long nStartPos; //File Snippet Start Position TfqQh!Y
long nEndPos; //File Snippet End Position NpYzN|W:
int nThreadID; //Thread's ID [ f`V_1d3
boolean bDownOver = false; //Downing is over "npLl]XM
boolean bStop = false; //Stop identical VBI~U?0
FileAccessI fileAccessI = null; //File Access interface b$'}IWNV
u:D,\`;)
J;7O`5J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mGqT_
{ fRd^@@,[
this.sURL = sURL; v/WvT!6V`
this.nStartPos = nStart; Gd%E337d
this.nEndPos = nEnd; ~!W{C_*N
nThreadID = id; _8"%nV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qU,u(El
} 6'qC *r
m%km@G$
>~k"C,6
public void run() YV>]c9!q
{ X Sw0t8
while(nStartPos < nEndPos && !bStop) 2N:|BO>
{ cp>1b8l6?
l>O~^41[
r+%}XS%;h
try{ *R6Ed
URL url = new URL(sURL); K0O&-v0"1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lZ9rB^!
httpConnection.setRequestProperty("User-Agent","NetFox"); P>3 ;M'KsO
String sProperty = "bytes="+nStartPos+"-"; /a!M6:,pX
httpConnection.setRequestProperty("RANGE",sProperty); i>68gfx
Utility.log(sProperty); .0>2j(
aM|^t:
s!j[Ovtx
InputStream input = httpConnection.getInputStream(); _]whHS+
//logResponseHead(httpConnection); 6vQCghI
!nkjp[p
5L4{8X0X8
byte[] b = new byte[1024]; 3KW4 ]qo~
int nRead; gK8{=A0c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zn'F9rWx>
{ F"<TV&xf
nStartPos += fileAccessI.write(b,0,nRead); &{c.JDO
//if(nThreadID == 1) hf~'EdU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GF-\WD
} o1kY|cnGH
89[5a
ub/9T-#l
Utility.log("Thread " + nThreadID + " is over!"); = j,Hxq
bDownOver = true; Y[ciT)
//nPos = fileAccessI.write (b,0,nRead); TxD,A0
} 2\p8U#""
catch(Exception e){e.printStackTrace ();} 9zKrFqhNo
} r2]KP(T8|
} R6A{u(
=k\V~8XZ
%cl=n!T
//打印回应的头信息 |aovZ/b4
public void logResponseHead(HttpURLConnection con) :Ej#qYi
{ )E.!jL:g
for(int i=1;;i++) rVE!mi]%
{ Pn*+g!`
String header=con.getHeaderFieldKey(i); ROyG+dUy
if(header!=null) As;@T$G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n@)Kf A)&
Utility.log(header+" : "+con.getHeaderField(header)); zMf.
else vO#=]J8`
break; D!- 78h
} dC7YVs_,#
} $-}a<UFE;
.m]"lH*
B8Cic\2
public void splitterStop() WDC+Jmlgp
{ ' R!pc
bStop = true; ueyz@{On~
} +;P8QZK6
75+#)hNa!P
;|.^_Xs
} J.r^"K\
-r6cK,WVU
t0 1@h_WS
/* ?9Eshw2
**FileAccess.java <GbF4\ue
*//文件访问(定位，写) S~9K'\vO
package NetFox; 3:Mq40]x
import java.io.*; w@&4dau
_bi]Bpxf
Z-fQ{&a{
public class FileAccessI implements Serializable{ c&{1Z&Y
.K=r.tf~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?+]prbt)
RandomAccessFile oSavedFile; 3~I|KF7x
long nPos; LX [_6
\{HbL,s
rff=ud>Jf
public FileAccessI() throws IOException \pXs&}%1,F
{ SM;*vkwz~
this("",0); p5C:MA~*
} e'FBV[e
"B~c/%#PH
'@$YX*[
public FileAccessI(String sName,long nPos) throws IOException 0UJ%tPS
{ WUwH W
oSavedFile = new RandomAccessFile(sName,"rw"); []'gIF
this.nPos = nPos; 8!~8:?6n
oSavedFile.seek(nPos); ! z^%$;p
} vdn`PS'#
qgT~yDm
CEwMPPYnD
public synchronized int write(byte[] b,int nStart,int nLen) |,3>A@
{ TSGJ2u5ie%
int n = -1; g[Z$\A?ZbZ
try{ uANG_sX^n
oSavedFile.write(b,nStart,nLen); jT~PwDSFt3
n = nLen; )U?Tmh
} tl 0_Sd
catch(IOException e) WF)(Q~op0U
{ G E=J Y
e.printStackTrace (); I~'%
} $2p=vi3
otA59 ;Z
-YXNB[C
return n; }e7os0;s
} o$*aAgS+
gx-ib/_f1
9{D u)k
} ZA u=m
DqfWu*
a'T8U1
/* `&\jOve
**SiteInfoBean.java 1ZL91'U
*/ qXOWCYqs
package NetFox; ae1?8man
zn,y'},
"!ZQ`yl
public class SiteInfoBean { HHT_}_?
R&>G6jZ?8
<G9HVMiP
private String sSiteURL; //Site's URL eP d
private String sFilePath; //Saved File's Path 03ol6y )C
private String sFileName; //Saved File's Name #ujry.m
private int nSplitter; //Count of Splited Downloading File J`E,Xw>2
`D44I;e^1;
q*L>MV
public SiteInfoBean() (Dy6I;S
{//nSplitter的缺省值为5 U$*AV<{%
//default value of nSplitter is 5 Jy#c 6
this("","","",5); dRdI('
} bW]7$?acv
HE;}B!>
iyA=d{S;V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L701j.7"
{ 50s1o{xwc
sSiteURL= sURL; o1kTB&E4B
sFilePath = sPath; IhIz 7.|
sFileName = sName; %DK0s(*w0
this.nSplitter = nSpiltter; (yx^zW7
S!Alno
q9e(YX>
} &d%\&fCm(
X#ZQpo'h
b< dwf[
public String getSSiteURL() ',WnT:
{ "QKCZ8_C
return sSiteURL; og`rsl
} &$$o=Yg,
y%Q0* _
Bi.,@7|>
public void setSSiteURL(String value) j8cIpbp8x
{ ^n|yfvR
sSiteURL = value; 3X;k c>
} !^yH]v
<y S|\Z|
LD=eMk: ~
public String getSFilePath() 5NR@<FE
{ H[S}&l\D4
return sFilePath; ,QeJ;U
} ->^Ex`
_Gu;=H,~&
w4nU86oZYl
public void setSFilePath(String value) w)rd--9f
{ @%'1Jd7-Wp
sFilePath = value; ]<3n;*8k?
} !K8Kw W|X
wD\viuq0
g"Tb\
public String getSFileName() `hl8j\HV<}
{ kqH:H~sgD
return sFileName; eh39"s
} 0.aIcc
]\C wa9
Sl;[9l2
public void setSFileName(String value) 2 rFjYx8D!
{ ] 6X;&=H
sFileName = value; t/wo G9N
} qkM)zOZ^
g@O H,h/
E0*KKo%
public int getNSplitter() q4EOI
{ :`>$B?x+
return nSplitter; k-Z:z?M
} f7SMO-3a
e7Sp?>-d
"5!T-Z+F
public void setNSplitter(int nCount) kR+7JUq]
{ 68?>#o865
nSplitter = nCount; +SB>>
} :R-_EY$k6
} Q}: $F{
{>3J96
:cxA
/* EY`]""~8v
**Utility.java ${h1(ec8
*/ M ZAz= )-
package NetFox; S}b^_+UbP
hm\UqIt
kaT !
public class Utility { N>H#Ew@2U
(KLhF
EzeU-!|W
public Utility() :I{9k~
{ Ygbyia|
[[#R ry
B1V+CP3t
} 3#0y.. F
UQg_y3 #V
//线程睡眠 *Fg)`M3g
public static void sleep(int nSecond) 7w<e^H?
{ HU/2P`DGP
try{ PavW@
Thread.sleep(nSecond); L)n_ Q
} -@tj0OHg
catch(Exception e) uznYLS
{ =fy\W=c
e.printStackTrace (); v:P=t2q
} R.\]JvqO
} Ne)3@?
c{IL"B6>
//日志 I.'/!11>
public static void log(String sMsg) ' <?=!&\D
{ g%V#Z`*|
System.err.println(sMsg); sd"eu
} *10qP?0H
MH|F<$42
D4N(FZ0~
public static void log(int sMsg) i6f42]Jy
{ GkIhPn(d
System.err.println(sMsg); #+N_wIP4
} *b_Iby-ZD
} lGt:.p{NG
%^d<go^
=CW> ;h]
/* MGf*+!y,
**TestMethod.java +w7U7" xQ
*/ ~"_!O+Pj
package NetFox; O+|ipw*B%
V!(7=ku!`
@^<&LG5^
public class TestMethod { '"+Gn52#
%JH/|mA&|
TNckyP75u
public TestMethod() XDAP[V
{ ///xx/weblogic60b2_win.exe E+|K3EJ
try{ DgK*>A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m[%':^vSr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C=(Q0-+L|
SiteFileFetch fileFetch = new SiteFileFetch(bean); d'&OEGb<
fileFetch.start(); jhPbh5E
} 3d]~e
catch(Exception e){e.printStackTrace ();} vS"h`pL
TFm[sO0RZ
=1k%T{>
} [y}h
j{'_sI{{
JS/ChoU
public static void main(String[] args) g\?v 5
{ Lyf5Yf([-
new TestMethod(); t%G.i@{pkp
} f_$hK9I
} x[$KZGK+GL
点击下载更多相关资料