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)); oy90|.]G
} 3{o5AsVv
for(int i=0;i<nEndPos.length-1;i++) hamn9
{ vluA46c
nEndPos = nStartPos[i+1]; XYD}OddO
} )]Xj"V2
nEndPos[nEndPos.length-1] = nFileLength; V6'"J
} [4,=%ez
} y~_wr}.CS
2T!pFcc
;2K_u
//启动子线程 09y%FzV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7VkT(xnm
for(int i=0;i<nStartPos.length;i++) aL@myq.
{ VZNMom,Wr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;'!G?)PZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b;#Z/phix
nStartPos,nEndPos,i); mjUln8Jc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `"J=\3->
fileSplitterFetch.start(); qYj EQz
} X-Y:)UT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0sW=;R2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OgjSyzc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /5:C$ik
nEndPos = " + nFileLength); Sw~jyUEr
// fileSplitterFetch[nPos.length-1].start(); xMI4*4y(
,yW BO
D_r&B@4w
//等待子线程结束 hR"j[
//int count = 0; CSx V^
//是否结束while循环 U1<EAGo|
boolean breakWhile = false; ]v7f9MC'\
der'<Q.U:k
UCzIOxp}
while(!bStop) S0C 7'H%?#
{ Y9fktg.
write_nPos(); #N\kMJl$l
Utility.sleep(500); LU5e!bP
breakWhile = true; !MoJb#B3^]
t-gg,ttnA
p b:mw$XQ7
for(int i=0;i<nStartPos.length;i++) YX38*Ml+V
{ Ndq|Hkd
if(!fileSplitterFetch.bDownOver) ML?%s`
{ e W&;r&26
breakWhile = false; gZ6]\l]J{
break; uev$5jlX
} o9-b!I2
} )`?Es8uW
if(breakWhile) +$M%"=tk
break; qQC<oR
E,,)?^g
tW;?4}JR
//count++; kxU<?0
//if(count>4) 86!"b
// siteStop(); 7(B|NYq
} Z+h^ ie"g
"HTp1
-.=q6N4
System.err.println("文件下载结束！"); "2HSb5b"`
} rjfcZ@
catch(Exception e){e.printStackTrace ();} =pQA!u]QE
} *x3";%o
CYA#:
4G;FpWQm
//获得文件长度 [|PVq#(
public long getFileSize() x]|8
{ .8[B }S(
int nFileLength = -1; ')%Kv`hz
try{ %O-RhB4q
URL url = new URL(siteInfoBean.getSSiteURL()); iQsv^K!\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W,~s0a!
httpConnection.setRequestProperty("User-Agent","NetFox"); -:IG{3fnu
VF1)dd
+#~=QT9
int responseCode=httpConnection.getResponseCode(); >}{'{ Z &
if(responseCode>=400) g'G%BX
{ !<\"XxK+l
processErrorCode(responseCode); @cNBY7=
return -2; //-2 represent access is error SiJ0r @
} J9J[.6k8
/HR9(j6
't".~H_V
String sHeader; *oLAO/)n
{B$cd?}
_[}r2,e
for(int i=1;;i++) 7n W*3(
{ uJVu:E.#1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EacqQFErl
//Utility.log(in.readLine()); '^pA%I2D
sHeader=httpConnection.getHeaderFieldKey(i); |}zvCD
if(sHeader!=null) .`4N#EjP
{ _%#Q \D
if(sHeader.equals("Content-Length")) -'&4No
{ Ezw(J[).C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x9}D2Ui
break; :<Z*WoEmt
} n|`L>@aw,
} K$_Rno"
else Qd"{2>
break; Rz% Px:M
} }m NP[L
} e;8>/G
catch(IOException e){e.printStackTrace ();} ;EstUs3
catch(Exception e){e.printStackTrace ();} ;}),6R
ZM"J5}h
z#*M}RR
Utility.log(nFileLength); >xu}eWSz
QW :-q(s
^L}fj$
return nFileLength; O)C y4[
} <]I[|4J 7
b%>vhj&F
U1(<1eTyu
//保存下载信息（文件指针位置） hU=n>g>nx
private void write_nPos() /C"dwh"``
{ T)Z2=5V
try{ 9u<4Q_I`
output = new DataOutputStream(new FileOutputStream(tmpFile)); =)5eui>{
output.writeInt(nStartPos.length); XE);oL2xP
for(int i=0;i<nStartPos.length;i++) #UGtYD}"
{ a.)Gd]}g
// output.writeLong(nPos); 5_";EED
output.writeLong(fileSplitterFetch.nStartPos); TA;
output.writeLong(fileSplitterFetch.nEndPos); 8mTjf Br
} `?VtB!p@x=
output.close(); :Bc)1^I
} U085qKyCw
catch(IOException e){e.printStackTrace ();} +T:F :X`
catch(Exception e){e.printStackTrace ();} +P,hT
} \IY)2C<e
T'.U?G
p~1,[]k
//读取保存的下载信息（文件指针位置） J1DX}h]
private void read_nPos() b*=eMcd
{ PY7j uS[+
try{ H&\IgD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :NJb<%$
int nCount = input.readInt(); *IWO ,!
nStartPos = new long[nCount]; z VleJ!d
nEndPos = new long[nCount]; @F)51$Ld
for(int i=0;i<nStartPos.length;i++) A2 r1%}{
{ )@)wcf!b
nStartPos = input.readLong(); FNlzpCT~L
nEndPos = input.readLong(); 6LZ(bP'd;
} ]CyWL6z
input.close(); ^sIxR*C[v
} {M:Fsay>p
catch(IOException e){e.printStackTrace ();} cl4`FU
catch(Exception e){e.printStackTrace ();} 5]cmDk
} [?uiM^&
,Zs:e.
GKdQ
private void processErrorCode(int nErrorCode) vy W/f
{ 1zNH[
System.err.println("Error Code : " + nErrorCode); # JHicx\8l
} zOA{S~>
nWpqAb
/h'V1zL#
//停止文件下载 oLVy?M%{P
public void siteStop() H%NP4pK
{ B$A`-
bStop = true; Lf_`8Ux
for(int i=0;i<nStartPos.length;i++) `` (D01<
fileSplitterFetch.splitterStop(); 0/?V _
1iBOf8
5Z{i't0CQ
} pk2OZ,14Mj
} jSVIO v:
//负责部分文件的抓取 ]S+NH[g+
**FileSplitterFetch.java HJ[@;F|aU
*/ Y6L_ _ RT
package NetFox; |&Gm.[IX;q
xI?%.Z;*+
x5\C MWW
import java.io.*; )G6{JL-I
import java.net.*; UD1R_bL}
~oO>6
xaQ]Vjw
public class FileSplitterFetch extends Thread { eqD|3YX
-g8G47piX:
K!^x+B|
String sURL; //File URL $%!'c# F
long nStartPos; //File Snippet Start Position -'btKz*9
long nEndPos; //File Snippet End Position $p@V1"x
int nThreadID; //Thread's ID 6|gC##T
boolean bDownOver = false; //Downing is over @,0W(
boolean bStop = false; //Stop identical Pe[~kog,TP
FileAccessI fileAccessI = null; //File Access interface Yt79W
?)<DEu:Y
^(7<L<H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y]$%>N0vLX
{ Dz$GPA
this.sURL = sURL; U{(B)dFTH
this.nStartPos = nStart; $%9.qy\8
this.nEndPos = nEnd; EJ7}h?a]U_
nThreadID = id; ^eke,,~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L+y}hb r
} &P'cf|KI
(VeX[*}I
b 'p0T1K(
public void run() 4PG]L`J{
{ \fG?j@Qx
while(nStartPos < nEndPos && !bStop) Htd-E^/
{ KhK:%1po
`l+{jrRb<
sd|5oz)
try{ kj_o I5<'
URL url = new URL(sURL); =`fJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -_&"Q4FR;+
httpConnection.setRequestProperty("User-Agent","NetFox"); 5,
String sProperty = "bytes="+nStartPos+"-"; ?K]Cs&E4
httpConnection.setRequestProperty("RANGE",sProperty); #(6^1S%
Utility.log(sProperty); Sx{vZS3
apsR26\^
G3O`r8oZcJ
InputStream input = httpConnection.getInputStream(); Gs^hqT;h
//logResponseHead(httpConnection); Wj0=cIb
n[$bk_S
|HhqWja
byte[] b = new byte[1024]; J`/t;xk
int nRead; >*/\Pg6^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q~_DR4xZ
{ It$'6HV~Sb
nStartPos += fileAccessI.write(b,0,nRead); # +OEO
//if(nThreadID == 1) Q/'jwyj_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K,f*}1$qM
} M*ZR+pq,
)`;Q]?D
c^$_epc*
Utility.log("Thread " + nThreadID + " is over!"); LLE\;,bv
bDownOver = true; dO/iL7K&
//nPos = fileAccessI.write (b,0,nRead); rH@{[~p
} m~`d<RM/
catch(Exception e){e.printStackTrace ();} rqJ'm?>cr
} cm`Jr#kl{
} B!:%^S
yV`H_iC
9eOP:/'}w
//打印回应的头信息 .W4P/Pw'
public void logResponseHead(HttpURLConnection con) -|s w\Q
{ mO];+=3v8
for(int i=1;;i++) 39 D!e&
{ Cu*+E%P9`
String header=con.getHeaderFieldKey(i); SM%N]/@U
if(header!=null) 7wKN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FKhmg&+>
Utility.log(header+" : "+con.getHeaderField(header)); 'T G43^
else }G8gk"st
break; z4GcS/3K
} )UBU|uYR\
} %eK=5Er jx
Sg#$ B#g
x"/DCcZ
public void splitterStop() k:1p:&*m
{ KO*# ^+g
bStop = true; KZ8Hp=s
} 3<Qe'd ^
%t&
k@[\C`P
} n=t50/jV3=
|qUi9#NUo
25e*W>SLw
/* OH.lAF4E(
**FileAccess.java 'OrGt_U
*//文件访问(定位，写) )Z4ilpU,
package NetFox; c*>8VW>
import java.io.*; }STTDq4
>4n\
Kkfza
public class FileAccessI implements Serializable{ *uJ0ZO9
o[$~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e@6]rl
RandomAccessFile oSavedFile; 5"~F#vt
long nPos; 8PKUg "p
6z-ZJ|?
NUSb7<s,&Y
public FileAccessI() throws IOException D\13fjjHlu
{ V\1pn7~V
this("",0); dnEIR5%+.
} =@e3I)D#?i
SX/E@vYb
Os)jfKn2
public FileAccessI(String sName,long nPos) throws IOException 2A>s a3\
{ ,\fp.K<
oSavedFile = new RandomAccessFile(sName,"rw"); *A<vrkHz
this.nPos = nPos; \zCw&#D0Z
oSavedFile.seek(nPos); g&E3Wc
} <b JF&,
:mYVHLmea
c{"=p8F_
public synchronized int write(byte[] b,int nStart,int nLen) {J&[JA\
{ ?nf!sJ'm
int n = -1; =6.4
try{ /)+V(Jlu
oSavedFile.write(b,nStart,nLen); T`ofj7$:
n = nLen; G 6r2 "
} Jy^.L$bt
catch(IOException e) .ei5+?V<i
{ _%R]TlL
e.printStackTrace (); :P'M|U
} pY~/<lzW
4D'AAr57
)6!ji]c N
return n; Zk:Kux[7
} OrC}WMhd
*JD-|mK
If>bE!_BO
} Mg"e$m
,1K`w:uhS
_O,k0O
/* Q[n*ce7L0
**SiteInfoBean.java }Fq~!D Ee
*/ W1;QPdz:
package NetFox; Xp67l!{v
>TQNrS^$J
\rpXG9
public class SiteInfoBean { ;2y4^
=&K8~
iNCT(N~.
private String sSiteURL; //Site's URL f>CJ1;][{
private String sFilePath; //Saved File's Path ;% <[*T:*'
private String sFileName; //Saved File's Name K[q{)>,9
private int nSplitter; //Count of Splited Downloading File oKMr Pr[`
7 /6Zp?
zG* >g
public SiteInfoBean() N^Hj%5
{//nSplitter的缺省值为5 jk\z-hd
//default value of nSplitter is 5 '.B5CQ
this("","","",5); fxQ4kiI
} `GUGy.b
"Snt~:W>
pN4gHi=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?hmuAgOtbh
{ 8wEUly
sSiteURL= sURL; XN&cM,
sFilePath = sPath; \\ZCi`O
sFileName = sName; ]N;\AXZ7
this.nSplitter = nSpiltter; gyz_$T@x
X,A]<$ACu%
,;@vVm'}
} $TX]*hNn
-=WQed}
9;7|MPbR
public String getSSiteURL() (V x2*Aw]
{ OLZs}N+;]
return sSiteURL; Gk']Ma2J}
} G' '9eV$
B#;6z%WK
dQs>=(|t
public void setSSiteURL(String value) a=4 `C*)
{ r_hs_n!6
sSiteURL = value; >ZwDcuJ~Lz
} *djVOC
)^`V{iD
`iNH`:[w
public String getSFilePath() lyD=n
{ U#G<cV79
return sFilePath; 2!_DkE
} .TM. v5B
2Krh&
SE$~Wbj?
public void setSFilePath(String value) /.WIED}>
{ g#q7~#9
sFilePath = value; UOpSH{N
} ^o87qr0g]
zRMz8IC.
r"9hpZH
public String getSFileName() I {%Y0S
{ R > [2*o"
return sFileName; Lz&FywF-l
} D>-srzw
7<ZGNxZ~
gHtflS
public void setSFileName(String value) f hjlt#
{ hTQ8y10a
sFileName = value; (?xR<]~g*
} y8ODoXk
,R\ex =c
&u!MI
public int getNSplitter() -asjBSo*D
{ tM|/OJ7
return nSplitter; t)5.m}
} if?X^j0
S6<#] 6Z
=h70!) Z5
public void setNSplitter(int nCount) DYF(O-hJK
{ QM'|k6
nSplitter = nCount; "%YVAaN
} kX2Z@ w`
} yAFt|<
;\(LovUy6
*nK4XgD
/* lA`qB1x
**Utility.java d`,z4_
*/ l{gR6U{e
package NetFox; i#aKW'
o)GesgxFa5
#w@FBFr@
public class Utility { |\Q2L;4C
{PkR6.XhR
&Oc `|r*
public Utility() fRb
{ /:v}Ni"6nF
`-.6;T}2U
D_?dy4\
} 82 dmlPwJC
:NL[NbQYt
//线程睡眠 J|F!$m{
public static void sleep(int nSecond) ?[|A sw1t
{ "(iDUl
try{ au]W*;x
Thread.sleep(nSecond); $:yIe.F
} 'h@&rr@5
catch(Exception e) oE_*hp+
{ v 8EI
e.printStackTrace (); Nt;1&dwUb
} e)y+]
} /#z"c]#
9C8 G(r
//日志 $o.;}
public static void log(String sMsg) r0@s3/
{ xSqr=^
System.err.println(sMsg); *&tTiv{^
} +s6v!({Z
E5#ff5
H|$ *HQm
public static void log(int sMsg) GO.7IL{{
{ P'o]#Az
System.err.println(sMsg); B6j/"x6N15
} ]4r&Q4d>O
} c_>AbF{
]a`"O
|S~$IFN4
/* gb4$W@N7V
**TestMethod.java Ljiw9*ZI
*/ >xA(*7
package NetFox; hT,rcIkg:
mfF `K2R
XH(-anU"!P
public class TestMethod { Y DW^N]G
)#GF:.B
x3( ->?)D
public TestMethod() <$pv;]n
{ ///xx/weblogic60b2_win.exe cL!A,+S[_
try{ u\MxQIo'u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '@ p464
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :xTm-L
SiteFileFetch fileFetch = new SiteFileFetch(bean); (74y2U6
fileFetch.start(); V2xvuDHI
} BPl% SL
catch(Exception e){e.printStackTrace ();} "LH!Trl@k
e2BC2K0
f`*VNB`
} WgG$ r
)#1!%aQ
2#00<t\
public static void main(String[] args) 4"3.7.<Q`
{ }D?qj3?bj
new TestMethod(); SSbx[<E3
} ^7*7^<
} uL@%M8n
点击下载更多相关资料