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)); -L?% o_
} 8z8SwWS?
for(int i=0;i<nEndPos.length-1;i++) 91d`LsP
{ v^_]W3K
nEndPos = nStartPos[i+1]; PVc|y.
} YPDsE&,J)
nEndPos[nEndPos.length-1] = nFileLength; 'N ::MN
} W<]Oo]
} .r%|RWs6W
S&]<;N_B
~<[5uZIo
//启动子线程 g4SYG)'R+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dS_)ll.6z
for(int i=0;i<nStartPos.length;i++) {59VS Nl
{ LEnP"o9ZW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ixHZX<6zYT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GiO#1gA
nStartPos,nEndPos,i); 9OT4jAm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UA4d|^ev
fileSplitterFetch.start(); 4?M3#],'h
} <O)X89dFM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MXJ9,U{<C'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P^m 6di
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 02#Iip3t
nEndPos = " + nFileLength); D4]B>
// fileSplitterFetch[nPos.length-1].start(); aC Lg~g4
7oLf5V1~
8 E+C:"
//等待子线程结束 8Pr7aT:,
//int count = 0; #L= eK8^e
//是否结束while循环 b<V./rWIB
boolean breakWhile = false; nEcd+7(
@&xaaqQ-
Il`k]XM
while(!bStop) "mK i$FV
{ p't:bR
write_nPos(); 4FE@s0M,
Utility.sleep(500); pW--^aHu
breakWhile = true; 4|41^B5Y
1 u_24
bKMR7&e.Ep
for(int i=0;i<nStartPos.length;i++) 4'hcHdL9
{ {!eANm'
if(!fileSplitterFetch.bDownOver) X<}o> 6|d
{ agU!D[M_G
breakWhile = false; :8-gm"awL5
break; XL/oy'_
} =>ztBw\
} <CKmMZ{
if(breakWhile) aGk%I
break; U;Ll.BFP
grxl{uIC8
,\9mAt1O
//count++; e=jT]i*cU
//if(count>4) ^N2M/B|0
// siteStop(); BS,5W]ervE
} dGD^op,6g
DEQE7.]3q
dJ%Rk#?;A
System.err.println("文件下载结束！"); M$4=q((0
} XZdr`$zf
catch(Exception e){e.printStackTrace ();} b801OF
} |~bR.IA
DMcxa.Sd!
W aGcoj
//获得文件长度 X})Imk7&E
public long getFileSize() q&Tn>B
{ H~dHVQtJZ
int nFileLength = -1; =Wk/q_.
try{ e_~fJ
URL url = new URL(siteInfoBean.getSSiteURL()); zIm_7\e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c(V=.+J
httpConnection.setRequestProperty("User-Agent","NetFox"); N>pmhskN?
H1%[\X?=
g?[&0r1
int responseCode=httpConnection.getResponseCode(); 71.\`'
if(responseCode>=400) oAZF3h]po
{ H&=n:'k^
processErrorCode(responseCode); sLAuR
return -2; //-2 represent access is error k8 ;uC~L
} ;64mf`
(YYj3#|
8lWH=kA\
String sHeader; o!toO&=
{`H<=h__
M9s43XL(&
for(int i=1;;i++) m&`(pf4A
{ 4OOn,09
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \SiHrr5
//Utility.log(in.readLine()); S2 "=B&,}
sHeader=httpConnection.getHeaderFieldKey(i); m UWkb
if(sHeader!=null) =0PRAc
{ B?#kW!wj
if(sHeader.equals("Content-Length")) bKuj po6
{ C3\E.u?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "7yNKO;W
break; [l':G]
} y5/'!L)g
} ^6aS]t
else *K,hrpYR
break; pFJQ7Jlx
} ! FR%QGn1
} x9)aBB
catch(IOException e){e.printStackTrace ();} Ob8B
catch(Exception e){e.printStackTrace ();} k]Alp;hVd
%h"qMs S
GjeUUmr
Utility.log(nFileLength); Cx+WLD
`D)Lzm R
,]Ro',A&
return nFileLength; )>y k-
} v0Ai!#
^IVe[P'
&@% b?~
//保存下载信息（文件指针位置） (rr}Pv%yb
private void write_nPos() Gg9VS&VI
{ j1puB
try{ -Aa]aDAz68
output = new DataOutputStream(new FileOutputStream(tmpFile)); zUs~V`0
output.writeInt(nStartPos.length); `k(u:yGK
for(int i=0;i<nStartPos.length;i++) OQ(D5GR:4
{ o#xgrMB
// output.writeLong(nPos); LZM,QQ
output.writeLong(fileSplitterFetch.nStartPos); !8Z2X!$m{<
output.writeLong(fileSplitterFetch.nEndPos); }3f BY@
} hhpv\1h#
output.close(); &:c:9w
} F<Hqo>G
catch(IOException e){e.printStackTrace ();} y !<'rg
catch(Exception e){e.printStackTrace ();} .!(,$'(@=
} aXdf>2c{JD
#e.jY_
K4!P'
//读取保存的下载信息（文件指针位置） J]}FC{CD!
private void read_nPos() 2yln7[a
{ 6ORY`Pe7P|
try{ *me,(C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xMDrE?
int nCount = input.readInt(); *O@sh
nStartPos = new long[nCount]; }iilzE4oH#
nEndPos = new long[nCount]; \Z)#lF|^
for(int i=0;i<nStartPos.length;i++) 'aD6>8/Hj
{ #>8T*B
nStartPos = input.readLong(); N5nvL)a~
nEndPos = input.readLong(); >dpbCPJ9[
} Ag0]U
input.close(); ~ww?Emrw
} $ph0ag+
catch(IOException e){e.printStackTrace ();} [kbC'Eh*
catch(Exception e){e.printStackTrace ();} YP[LQ>
} NJZXs_%>$
n6b3E*
[@m[V1D
private void processErrorCode(int nErrorCode) F`!TV(,bY
{ %O#)Nq>mp
System.err.println("Error Code : " + nErrorCode); HWqLcQ d:P
} N-[n\}'
"JkZJ#
C"6Amnj
//停止文件下载 L@w0N)P<!{
public void siteStop() )`w=qCn1Y
{ q0&Wk"X%rr
bStop = true; <rNtY,
for(int i=0;i<nStartPos.length;i++) ht?CHUu
fileSplitterFetch.splitterStop(); n0_B(997*
: *ERRSL)
Nd`HB=ShJ
} R0%?:! F
} xE%O:a?S
//负责部分文件的抓取 OI+E (nA
**FileSplitterFetch.java %drJ p6n%
*/ 3&es]1b
package NetFox; {G]?{c)"
lDo(@nM
bA9CO\Pp`
import java.io.*; $^t<9"t
import java.net.*; ,Ij=b
bSQRLxF
O -G1})$
public class FileSplitterFetch extends Thread { n ]w7Zj
)S^z+3p
J"-_{)0lD
String sURL; //File URL R1}IeeZO?&
long nStartPos; //File Snippet Start Position vF"c
long nEndPos; //File Snippet End Position 5^yG2&>#
int nThreadID; //Thread's ID K<FKu $=
boolean bDownOver = false; //Downing is over @7-=zt+f
boolean bStop = false; //Stop identical uJgI<l'|e3
FileAccessI fileAccessI = null; //File Access interface LZ{YmD&6]
`)6>nPr7P
?cJY B)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h1#S+k
{ 80Ag
this.sURL = sURL; lr WLN
this.nStartPos = nStart; 34SA~5
this.nEndPos = nEnd; E#8_hT]5
nThreadID = id; gI)u}JX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R2l[Q){!
} rJDnuR
2}w#3K
)R~aA#<>
public void run() ?w*yW;V`
{ gQy~kctQ#
while(nStartPos < nEndPos && !bStop) <;%0T xK|U
{ E/ijvuO
rj3YTu`
8W;2oQN7
try{ Zd[OWF
URL url = new URL(sURL); 3YW=||;|Yg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p#bhz5&/
httpConnection.setRequestProperty("User-Agent","NetFox"); ryg4hHspl
String sProperty = "bytes="+nStartPos+"-"; [ByQ;s5tY
httpConnection.setRequestProperty("RANGE",sProperty); oU8>Llt=$
Utility.log(sProperty); l4KbTKm7
Hd*}k6
tjj^O%SV<
InputStream input = httpConnection.getInputStream(); &1_U1
//logResponseHead(httpConnection); nd:E9:
#zt*xS[{0
H-(q#?:
byte[] b = new byte[1024]; )Vg2Jix,]
int nRead; ~].ggcl`w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "mOI!xf@a
{ x`2| }AP(
nStartPos += fileAccessI.write(b,0,nRead); kh3<V'k]
//if(nThreadID == 1) !2$ z *C2;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @u/H8\.l
} dCeX}Z
fywvJ$HD]L
:I \9YzSs@
Utility.log("Thread " + nThreadID + " is over!"); (bv,02
bDownOver = true; hL!QLiF:
//nPos = fileAccessI.write (b,0,nRead); zmiZ]uq
} h*3{6X#(/
catch(Exception e){e.printStackTrace ();} A2NF<ZsD
} 'tm$q/&
} g6%Z)5D]!
b}@(m$W
vX;HC'%n
//打印回应的头信息 ,3HcCuT
public void logResponseHead(HttpURLConnection con) , ECLqs%
{ a }'->H
for(int i=1;;i++) (e9fm|n!)|
{ +?[BU<X6u
String header=con.getHeaderFieldKey(i); f8'MP9Lv
if(header!=null) .et ^4V3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KzphNHd
Utility.log(header+" : "+con.getHeaderField(header)); 0/ !,Dn
else !8R@@,_v
break; }HRK?.Vj:
} *5OCqU+g
} Cqxv"NN
+@<KC
JYm7@gx
public void splitterStop() ghAi{@s$)
{ Hx2En:^Gf
bStop = true; I%"'*7U
} c#lPc>0xb
-.iNNM&a
|cDszoT /
} r&%.z*q
MT6/2d
P`jL]x
/* Wto;bd
**FileAccess.java C5@V/vA
*//文件访问(定位，写) (K :]7
package NetFox; = 96P7#%
import java.io.*; iev>9j
>MG(qi
r-IT(DzkD
public class FileAccessI implements Serializable{ s-*._;
4woO;Gm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iiG f'@/
RandomAccessFile oSavedFile; 8K{[2O7i)
long nPos; 1A<,TFg
q; jiw#_
~n?>[88"
public FileAccessI() throws IOException BqH]-'1G
{ c</1
this("",0); qAY%nA>jO
} /nZ;v4
uD9|.P}
wRtZ`o
public FileAccessI(String sName,long nPos) throws IOException /i_ @
{ rwE%G>Vb
oSavedFile = new RandomAccessFile(sName,"rw"); 7N=-Y>$X
this.nPos = nPos; j1-,Sqi
oSavedFile.seek(nPos); q,%:h`t\
} hs+kr?Pg`
T vtm`Yk\
{9LWUCpsf
public synchronized int write(byte[] b,int nStart,int nLen) Bs;|D
{ PdeBDFWD
int n = -1; )]43R
try{ JC#>Td
oSavedFile.write(b,nStart,nLen); .S?pG_n]f
n = nLen; 89~ =eY
} |=dC )Azs
catch(IOException e) D@oCP =m<
{ {ZsdLF#
e.printStackTrace (); 0?0Jz
} %rkk>m
`ln1$
D y-S98Y
return n; ]J7Qgp)i
} x@>&IBiL
n_nl{
5nlMrK
} \qh*E#j
^aZAw%K
>~nF=
/* 58tVx'1y
**SiteInfoBean.java h8e757z
*/ w5=tlb
package NetFox; PVOx`<ng
3)=c]@N0
ANi)q$:{
public class SiteInfoBean { [ ho(z30k
xiblPF_n3
.dMVoG5
private String sSiteURL; //Site's URL t.Nb?/
private String sFilePath; //Saved File's Path .;7> y7$*
private String sFileName; //Saved File's Name E:`v+S_h
private int nSplitter; //Count of Splited Downloading File %@"!8Y(j
]D2udeg
jE2}p-2Q0
public SiteInfoBean() 9=X)ung9
{//nSplitter的缺省值为5 LE6.nmvS
//default value of nSplitter is 5 ^' M>r(t
this("","","",5); q`NXJf=sc
} {'En\e
txgQ"MGA%
aGZi9O7G}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3r+.N
{ X0(tboj#
sSiteURL= sURL; Y?J"wdWJNB
sFilePath = sPath; /4\wn?f
sFileName = sName; cTTW06^
this.nSplitter = nSpiltter; 3*UR3!Z9 *
LUX*P7*B
!k3e\v|
} yifY%!@Xu
?p<.Fv8.
uw(NG.4
public String getSSiteURL() &fa5laJb
{ 7CXW#H
return sSiteURL; C'yppl%
} }Ew hj>w
j^tW Iz
39wa|:I
public void setSSiteURL(String value) Vwk#qgnX
{ %UUH"
sSiteURL = value; B.r4$:+jb2
} Ian[LbCWB
QqNW}:#
c9qR'2
public String getSFilePath() j]|U
{ HB+|WW t>
return sFilePath; EtbnE*S
} b$%0.s
x<Vm5j
2d%}- nw
public void setSFilePath(String value) ZF7IL
{ @fv}G>t
sFilePath = value; ez]tAW
} <f@"HG l
zZcnijWb
40E#JF#
public String getSFileName() k>x&Ip8p
{ ;Gx)Noo/>
return sFileName; O$/o'"@ /
} 9O{b]=>wq
l3Njq^T
y[B>~m8$
public void setSFileName(String value) ~/^5) g_
{ _Z5Mw+=19
sFileName = value; \`V;z~@iA
} #mize
{7TlN.(
KL$bqgc(p3
public int getNSplitter() ^7zu<lX
{ 1I@8A>2^OX
return nSplitter; N7E$G{TT
} _@S`5;4x
|@NiW\O
T91moRv
public void setNSplitter(int nCount) niB`2J
{ z[`@}}Q
nSplitter = nCount; Zo1,1O
} ;XM{o:1Y[
} F}Vr:~
2'=T[<nNB
s3 7'&K
/* Z{&cuo.@<]
**Utility.java s0Z uWVip
*/ X7k.zlH7T
package NetFox; @(r/dZc
hI9
>pUtwIP
public class Utility { jZ NOt
bfo["
PkI:*\R
public Utility() Q.K,%(^;a
{ &0f5:M{P
vfVj=DYj
8@so"d2e
} y;/VB,4V
(o3 Iy
//线程睡眠 jKt7M>P
public static void sleep(int nSecond) l;o1 d-n]
{ II6CHjW`;
try{ MEB it
Thread.sleep(nSecond); cnTaJ/o
} I? ,>DHUX
catch(Exception e) I`NjqyTW
{ $DG?M6
e.printStackTrace (); ~69&6C1Ch
} e7wSOs
} P.gb1$7<
]U"94S U:)
//日志 bhniB@<
public static void log(String sMsg) 13taFVdU
{ N7e"@Ic
System.err.println(sMsg); 03C0L&
} ]+X@ 7
s[UHe{^T
-GxaV #{
public static void log(int sMsg) B}^w_C2
{ Hh+ 2mkg
System.err.println(sMsg); eM8}X[
} <)1qt 9
} F$)[kP,wtO
82l~G;.n3
Bve.C
/* HTG%t/S
**TestMethod.java ti \wg
*/ }_ 9Cxji
package NetFox; d3xmtG {i
B_.%i+ZZ
'inFKy'H
public class TestMethod { zCk^B/j sM
EN/,5<S<,[
M3.do^ss
public TestMethod() {.XEL
{ ///xx/weblogic60b2_win.exe YPxM<Gfa8
try{ .SWlp2!M5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _*f`iu:`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (!:,+*YY
SiteFileFetch fileFetch = new SiteFileFetch(bean); =i[\-
fileFetch.start(); 7Op>i,HZk\
} ui?
catch(Exception e){e.printStackTrace ();} &v@a5L
LGn:c;
B6={&7U2
} 'dn]rV0(C
!z>6Uf!{
2'w?\{}D
public static void main(String[] args) ~sh`r{0
{ ?32&]iM oW
new TestMethod(); w(L4A0K[
} :=Nz}mUV
} ')cMiX\v
点击下载更多相关资料