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)); T}?vp~./
} w'Kc#2
for(int i=0;i<nEndPos.length-1;i++) C&\vVNV;9
{ P p}N-me>_
nEndPos = nStartPos[i+1]; Z1(-FT6O
} T@GR Tg
nEndPos[nEndPos.length-1] = nFileLength; ()E:gqQ
} +hz^( I7
} )>! IY Q
'm;M+:l 6
GisI/Ir[
//启动子线程 "/EE$eU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *L%i-Wg"
for(int i=0;i<nStartPos.length;i++) B>^5h?(lt
{ +UK".
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )A`Zgg'L7D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]Tje6iF
nStartPos,nEndPos,i); gAx8r-` `
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ) OqQz7'
fileSplitterFetch.start(); -*?Y4}mK
} K|H&x"t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4LCgQS6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A/ eZ!"Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HzO6hb{jJO
nEndPos = " + nFileLength); YzcuS/~x
// fileSplitterFetch[nPos.length-1].start(); AX|-Gv
~dIb>[7wy
(okCZ-_Jn
//等待子线程结束 MuQBn7F{c
//int count = 0; E0nR Vg
//是否结束while循环 _HT*>-B
boolean breakWhile = false; 0I.9m[<Fc
3X+uJb2
!Q,A#N(
while(!bStop) S=Ihg
{ @~!1wPvF`I
write_nPos(); a<.7q1F
Utility.sleep(500); >.D0McQg
breakWhile = true; ;w(]z
+ *YGsM`E9
BO5gwvyI
for(int i=0;i<nStartPos.length;i++) %j].' ;
{ QK5y%bTSA
if(!fileSplitterFetch.bDownOver) 728}K^7:
{ iA~b[20&
breakWhile = false; WC!bB
break; ASuxty
} I#Q Tmg.
} o:\RJig<
if(breakWhile) TtL2}Wdd.%
break; Jmb [d\ /D
q%4l!gzF3
LE_1H>
//count++; $*| :A
//if(count>4) jafq(t
// siteStop(); VV(>e@Bc4
} mm3goIi;Y
n6gYZd
S7Xr~5>X
System.err.println("文件下载结束！"); J&{qe@^
} \C3ir&
catch(Exception e){e.printStackTrace ();} ?VMj;+'tr
} U~8.uldnF
S9Fg0E+J
w;.'>ORC
//获得文件长度 ZQvpkO7}M
public long getFileSize() mMqT-jT
{ $+IE`(Ckf
int nFileLength = -1; z8bDBoD6
try{ q+{-p?;;
URL url = new URL(siteInfoBean.getSSiteURL()); U[zY0B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,jBd3GdlZ
httpConnection.setRequestProperty("User-Agent","NetFox"); H_'i.t 'SS
YJw9 d]
oZ1#.o{
int responseCode=httpConnection.getResponseCode(); IMY?L
if(responseCode>=400) d7A08l{
{ pRtxyL"y
processErrorCode(responseCode); }>JFO:v&
return -2; //-2 represent access is error @GGzah#
} ZdEeY|j
a1p:~;f}[
DBl.bgf
String sHeader; 0fvQPs!O
,P^pDrc
Z*d8b
for(int i=1;;i++) #&.&Uu$
{ <^,w,A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2}u hPW+
//Utility.log(in.readLine()); Fzk
sHeader=httpConnection.getHeaderFieldKey(i); Y[gj2vNe4g
if(sHeader!=null) c'_-jdi`>_
{ f>JuxX\G
if(sHeader.equals("Content-Length")) pN<wO1\9
{ lgZ3=h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )5lo^Qb
break; b=a&!r5M
} xm>RLx}9
} DCb\=E
else ze Qgg|;
break; >9W ;u`
} . m_y5J
} L0SeG:
catch(IOException e){e.printStackTrace ();} &I.UEF2,
catch(Exception e){e.printStackTrace ();} *=L3bBu?
E%\iNU!
0SV#M6`GX
Utility.log(nFileLength); t=iSMe
-@%*~^~z'
(veGztt
return nFileLength; m~9Qx`fi`
} v'B++-%
o)KF+[^
QBa1c-Y
//保存下载信息（文件指针位置） CzxU @
private void write_nPos() 1TfK"\
{ hS&,Gm`^
try{ L)VEA8}
output = new DataOutputStream(new FileOutputStream(tmpFile)); )((Jnm D
output.writeInt(nStartPos.length); 2%N$Y]
for(int i=0;i<nStartPos.length;i++) nBL7LocvR
{ ~C< X~$y&
// output.writeLong(nPos); WO$PW`k
output.writeLong(fileSplitterFetch.nStartPos); v$"#9oh
output.writeLong(fileSplitterFetch.nEndPos); V\@h<%{^%7
} z8M^TV
output.close(); g^(wZ$NH
} 9iWDEk
catch(IOException e){e.printStackTrace ();} $j^Jj
catch(Exception e){e.printStackTrace ();} goi.'8M|/b
} (,PO(
gF1qZ=<
vpx8GiV
//读取保存的下载信息（文件指针位置） OA2<jrGB!
private void read_nPos() } ab@Nd$
{ PygT_-3z{
try{ $78fR8|r-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PJN TIa
int nCount = input.readInt(); au2ieZZ[
nStartPos = new long[nCount]; z %` \p
nEndPos = new long[nCount]; T%K(opISc(
for(int i=0;i<nStartPos.length;i++) XJsHy_6
{ =)m2u2c M
nStartPos = input.readLong(); UiA\J
nEndPos = input.readLong(); ~%_$e/T
} 9 )u*IGj
input.close(); 6 k+FTDL
} CJk$o K{Q
catch(IOException e){e.printStackTrace ();} H r?G_L
catch(Exception e){e.printStackTrace ();} .&.j?kb
} E\#hcvP
4H8vB^
AD=@
private void processErrorCode(int nErrorCode) /j./
{ {gluK#Qm
System.err.println("Error Code : " + nErrorCode); T5NO}bz
} Z5;1ySn{
0 V*Di2
~WU _u,:
//停止文件下载 U?JZ23>bbw
public void siteStop() {bL6%._C
{ ,Cj1S7GFR
bStop = true; /K2VSj3\
for(int i=0;i<nStartPos.length;i++) [wP;g'F
fileSplitterFetch.splitterStop(); w"$CV@AJ
R6]/g
,xB&{J
} d7qY(!&
} ,K .P,z~*
//负责部分文件的抓取 Ojq>4=Z\
**FileSplitterFetch.java uQWJ7Xm
*/ R_\{a*lV0
package NetFox; vb)Z&V6(
EsXCi2]1
EP&iG%(k
import java.io.*; KZzOs9 s
import java.net.*; }rsD$
MPA<?
s;X"E=
public class FileSplitterFetch extends Thread { !!4_x
dON4r2-yC
bgGd
String sURL; //File URL CE-ySIa
long nStartPos; //File Snippet Start Position br+{23&1R#
long nEndPos; //File Snippet End Position 'YQ"Lf
int nThreadID; //Thread's ID {NXc<0a(
boolean bDownOver = false; //Downing is over 6ND,4'6
boolean bStop = false; //Stop identical 7kO5hlKeo
FileAccessI fileAccessI = null; //File Access interface -}1S6dzr
;$l!mv7
L=3^A'|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @26H;
{ AZt~ \qf
this.sURL = sURL; /4+M0Pl
this.nStartPos = nStart; [c]X) @#S
this.nEndPos = nEnd; #o_`$'>
nThreadID = id; 12DMb9_rp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [t5:4 Iq
} S{{D G
vE7L> 7
BbUZ,X*Y
public void run() )`yxJ;O@$
{ "2(lgxhj
while(nStartPos < nEndPos && !bStop) ym:^Y-^iV
{ k1i*1Tc
y562g`"U
=K .'x
try{ pL8+gL
URL url = new URL(sURL); ]h~=lItTRZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1uz9zhG><
httpConnection.setRequestProperty("User-Agent","NetFox"); x0@J~ _0
String sProperty = "bytes="+nStartPos+"-"; A;m)/@
httpConnection.setRequestProperty("RANGE",sProperty); V;mKJ.d${
Utility.log(sProperty); l;}D| 6+_W
)VQ:L:1t(
Ox.&tW%@
InputStream input = httpConnection.getInputStream(); [[P?T^KT
//logResponseHead(httpConnection); yZ)GP!cM4c
E9HA8
2-j+-B|i
byte[] b = new byte[1024]; ,.uu/qV}w
int nRead; RzQ1Wq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 55MsF}p
{ 8:0QIkqk
nStartPos += fileAccessI.write(b,0,nRead); / *xP`'T
//if(nThreadID == 1) JVf8KHDj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `DIIJ<;g
} ^-cj=on=Q
hNmC(saMGm
A U9Y0<
Utility.log("Thread " + nThreadID + " is over!"); GLQ1rT
bDownOver = true; R<{bb'
//nPos = fileAccessI.write (b,0,nRead); G$XvxJ
} ~V[pu
catch(Exception e){e.printStackTrace ();} %sP C3L
} zg+78
} 1O*5>dkX;%
YpoO:
EWNh:<F?
//打印回应的头信息 zm) ]cq
public void logResponseHead(HttpURLConnection con) db$Th=s[
{ zvYkWaa_Qz
for(int i=1;;i++) xu(5U`K
{ )a.Y$![
String header=con.getHeaderFieldKey(i); m619bzFlB
if(header!=null) jhrmQS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4YM!SE-I
Utility.log(header+" : "+con.getHeaderField(header)); W_9-JM(r
else vt<r_&+ pJ
break; W,5A|Q~
} U(3+*'8r,1
} /+pbO-rW*
I>o+INb:
dawe!w!
public void splitterStop() vpcx 1t<
{ rM#jxAb
bStop = true; K@Q_q/(%;
} H_m(7@=
]c]rIOTN
asb-syqU
} *,5V;7OR
<uDEDb1|l
w'z?1M(*
/* 8M*[RlUJB
**FileAccess.java ]+;1)
*//文件访问(定位，写) 0ohpJh61Q
package NetFox; )$Xd#bzD|
import java.io.*; A9\m.3jo
Y,?s-AB
"- S2${
public class FileAccessI implements Serializable{ |E-/b6G
}NW^?37
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e}yoy+9
RandomAccessFile oSavedFile; r,X5@/
long nPos; {%5k1,/(
jm0J)Z_"nr
*#-X0}'s
public FileAccessI() throws IOException DKgwi'R
{ BlUl5mP}>
this("",0); m6tbN/EJZ
} {i y[8eLg
l4?o0;:)
lb ol+O65
public FileAccessI(String sName,long nPos) throws IOException 7;RhA5M
{ SO%x=W
oSavedFile = new RandomAccessFile(sName,"rw"); ,}2yxo;i
this.nPos = nPos; RQ}(}|1+\
oSavedFile.seek(nPos); %7%7 W*0d
} {I+
6I GUp
/1 lIV_Z
public synchronized int write(byte[] b,int nStart,int nLen) s `fIeP
{ u,e'5,`N
int n = -1; |#8u:rguy
try{ Q3> 3!FAO
oSavedFile.write(b,nStart,nLen); </F@5*
n = nLen; :W(3<D7\
} LWE[]1=
catch(IOException e) nlJ~Q_E(
{ o:B?gDM
e.printStackTrace (); . [DCL
} V{@ xhW0
.r[b!o^VR
H~E(~fl
return n; N p9N#m?
} 1| "s_m>g
6, \i0y5n
JR{3n*
} <Z5ak4P
YY-{&+,
nD6mLNi%a
/* CY;ML6c@
**SiteInfoBean.java G6K;3B
*/ (,1}P
package NetFox; b:3n)-V{u
08AC9
{Ts@#V=:
public class SiteInfoBean { N<o3pX2i]
._@Scd
vWY}+#
private String sSiteURL; //Site's URL BE. v+'c"
private String sFilePath; //Saved File's Path wLwAtjW)
private String sFileName; //Saved File's Name 1];rW`Bw
private int nSplitter; //Count of Splited Downloading File N"MK 0k
EeGP E
ModwJ w
public SiteInfoBean() c#sPM!!
{//nSplitter的缺省值为5 z3+y|nx!
//default value of nSplitter is 5 AY4ZU CqI
this("","","",5); ~01 o
} TP'
V\^rs41$;
/.<%y8v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D>M a3g
{ e^kccz2f
sSiteURL= sURL; 4DI.RK9
sFilePath = sPath; RG/M-
sFileName = sName; h- .V[]<
this.nSplitter = nSpiltter; 9,|{N(N<!
?95^&4Oh0
kG_ K&,;@
} gX<"-,5jc
N:'v^0
K=Z~$)Og)
public String getSSiteURL() p\I,P2on
{ (dD+?ZOO
return sSiteURL; #(&!^X3
} usEdp
gQaBQq9
9EzXf+f
public void setSSiteURL(String value) vmdu9"H
{ h(]aP<49L
sSiteURL = value; Dyv 6K_,
} v}p'vh^8B
h|OqM:J;
yO Ed8
public String getSFilePath() MGpP'G:v
{ D /ysS$!{
return sFilePath; FEj{/
} H.|v^e
`tA~"J$32l
K];`
public void setSFilePath(String value) j`jF{k b
{ !4-B xeNY\
sFilePath = value; 3wZA,Z
} HqNM31)
N,U<.{T=A
bM7y}P5`1
public String getSFileName() ]la8MaZ<
{ 5BKga1Q
return sFileName; OB"Ur-hJ0
} $YuVM
c{4C4'GD
:*|%g
public void setSFileName(String value) S*;8z}5<\
{ I^|6gaP|6
sFileName = value; fp!Ba
} ozN#LIM>P
R2{y1b$l
*Pj[r
public int getNSplitter() F<SMU4]YdG
{ ?K,xxH
return nSplitter; pvCn+y/U;
} "@: b'm
r.1/*i
$s$j</.q
public void setNSplitter(int nCount) h+EG) <
{ dqwCyYC
nSplitter = nCount; j2O?]M
} VZ"W_U,
} } :U'aa
eytd@-7uX
b37F;"G
/* H9'Y` -r
**Utility.java qOaI4JP@
*/ _ dFZR
package NetFox; o&45y&
=#)Zm?[;
t\LAotTF/
public class Utility { rPaUDR4U
s))L^|6
U~!yGjF
public Utility() %|mRib|<C
{ hE.NW
i'Vrx(y3
lGHU{7j\
} yt,xA;g
Brw-"tmx
//线程睡眠 lq0@)'D
public static void sleep(int nSecond) Y rq-(
{ a1V+doC
try{ 5IOMc4v
Thread.sleep(nSecond); 7/*Q?ic
} [@ExR*
catch(Exception e) #$q~ZKB
{ 1=LI))nV
e.printStackTrace (); TAfLC)
} 5 :O7cBr
} f-6hcd@Ca
}.md$N_F
//日志 kmHIU}Z
public static void log(String sMsg) +EI+@hS
{ JkT, i_
System.err.println(sMsg); VQSwRL3B=
} [I/f(GK
4`Com~`6"
>KF1]/y<
public static void log(int sMsg) *n9t~t6GHg
{ so[i"ZM)
System.err.println(sMsg); pfd||Z
} {}F?eI
} .hI3Uv8[
z?o16o-:
r$3{1HXc
/* O'tVZ!C#J
**TestMethod.java 9+'QH
*/ CKJ9YKu{W
package NetFox; /8V#6d_
&Xr@nt0H
:e9}k5kdk
public class TestMethod { tK9_]663
4 ZD~i e
02g!mJW>}y
public TestMethod() osKM3}Sb
{ ///xx/weblogic60b2_win.exe =#WoeWFW*
try{ ?.E ixGzI^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =HJ)!(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t;wfp>El
SiteFileFetch fileFetch = new SiteFileFetch(bean); w!$|IC
fileFetch.start(); K$>C*?R
} H.\gLIr
catch(Exception e){e.printStackTrace ();} C>%2'S^.b
Rw4"co6
(r8Rb*OP
} fiDwa ;,
W<Ms0
&,?bX])
public static void main(String[] args) f{ZOH<"Lo
{ 4;G:.k!K
new TestMethod(); :?1r.n
} J*)Vpk
} CiE
点击下载更多相关资料