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)); %,<Ki]F
} ."O%pL]!/b
for(int i=0;i<nEndPos.length-1;i++) h6?Z
{ z$~F9Es9
nEndPos = nStartPos[i+1]; I S'Uuuz7g
} %K=_
nEndPos[nEndPos.length-1] = nFileLength; .L;e:cvx
} X6(s][Wn
} FIVC~LDd
k.c.7%|~;
RP+)sCh
//启动子线程 2P^qZDG 8I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wi!"Vcn
for(int i=0;i<nStartPos.length;i++) TXyiCS3
{ Px*<-t|R-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), djw\%00&#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lsOfpJ
nStartPos,nEndPos,i); n{etDO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (dQ=i
fileSplitterFetch.start(); ,d*hhe
} 1iLU{m9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L1DH9wiQi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vp*+Ckd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #,6T.O
nEndPos = " + nFileLength); u-:3C<&>
// fileSplitterFetch[nPos.length-1].start(); ; Ad5Jk
5F ^VvzNn
lQ!OD&6
//等待子线程结束 %.$7-+:7A
//int count = 0; t&[<Dl/L
//是否结束while循环 >nih:5J,ja
boolean breakWhile = false; 9^8OIv?m8
]b sabS?
mK"s*tD
while(!bStop) to,\n"$~!
{ Fzt?M
write_nPos(); )$df6sq
Utility.sleep(500); @@{5]Y
breakWhile = true; o59$vX,
XGC\6?L~
vDi Opd
for(int i=0;i<nStartPos.length;i++) q-_!&kDK"
{ ^->S7[N?
if(!fileSplitterFetch.bDownOver) "&4r!2A
{ #)]t4wa_W
breakWhile = false; NsM`kZM4H
break; m~Q24Z]!'&
} k1zK3I&c_
} 5dE=M};v
if(breakWhile) PR$;*|@
break; ^i!6z2/
v0E6i!D/
|K-`
//count++; &{+0a[rN
//if(count>4) y5+%8#3
// siteStop(); {Y Y,{H
} 2E!~RjxSY
s<k2vbhI
?7LvJ8
System.err.println("文件下载结束！"); *x;4::'Jn
} ^IIy>
catch(Exception e){e.printStackTrace ();} v}V[sIs}
} nM b@ B
uZ-ZZE C
<9yh:1"X
//获得文件长度 u{\'/c7G
public long getFileSize() p:Lmf8EI
{ \#I$H9O
int nFileLength = -1; |C<#M<
try{ 25{_x3t^
URL url = new URL(siteInfoBean.getSSiteURL()); .1{{E8Fj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nR*' 3
httpConnection.setRequestProperty("User-Agent","NetFox"); Km%L1Cd]
.#|?-5q/iN
Q!U}
int responseCode=httpConnection.getResponseCode(); PS[ C!s&KE
if(responseCode>=400) }58MDpOF1
{ 8j3Y&m4^
processErrorCode(responseCode); NM![WvtjW
return -2; //-2 represent access is error )S2yU<6oOt
} s:"Sbml
=uAy/S
xHJkzI
String sHeader; zp1ym}9M
E8}evi
bG@2f"
for(int i=1;;i++) VLkAsM5}%
{ [{BY$"b#:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eJHh}
//Utility.log(in.readLine()); oR=i5lAU
sHeader=httpConnection.getHeaderFieldKey(i); |.UY'B
if(sHeader!=null) .\^0RyJE
{ U{hu7
if(sHeader.equals("Content-Length")) 8SKrpwy
{ er)I".|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B<m0YD?>~>
break; 0zq'Nf?#3
} #m{*]mY@
} u%)gnj_
else g)#{<#*2
break; G,|!&=Pe|E
} }>0>OqvF
} 6xJffl
catch(IOException e){e.printStackTrace ();} 9T24dofkJ
catch(Exception e){e.printStackTrace ();} sEdz`F
#H>{>0q
bP9ly9FH
Utility.log(nFileLength); @3O)#r}\
"yaxHd
y-1e(:GF
return nFileLength; AT~,
} E3wL n/<
&R_7]f+%)
`9J9[!+!`
//保存下载信息（文件指针位置） gK[;"R)4o@
private void write_nPos() tZ9i/=S
{ !V37ePFje
try{ FHSoj=
output = new DataOutputStream(new FileOutputStream(tmpFile)); V<0iYi;4=
output.writeInt(nStartPos.length); CPP~,E_
for(int i=0;i<nStartPos.length;i++) IFX$\+-
{ 0Lxz?R x]<
// output.writeLong(nPos); 8v& \F
output.writeLong(fileSplitterFetch.nStartPos); =W.}&
output.writeLong(fileSplitterFetch.nEndPos); ;J5z
} PWpt\g
output.close(); /;Tc]
} UPfO;Z`hJ
catch(IOException e){e.printStackTrace ();} s.}K?)mH
catch(Exception e){e.printStackTrace ();} 2(xC|
} 0d9z8y
-Qn7+?P
!-f Bw
//读取保存的下载信息（文件指针位置） \@:,A]
private void read_nPos() YS9RfK/
{ NFs5XpZ~
try{ :-k|jt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `R[ZY!=+
int nCount = input.readInt(); x.?5-3|d$
nStartPos = new long[nCount]; ,JV0ib,
nEndPos = new long[nCount]; 5XZ!yYB?
for(int i=0;i<nStartPos.length;i++) @%R<3!3v
{ '+cI W(F?
nStartPos = input.readLong(); }6c>BU}DF
nEndPos = input.readLong(); ijF_ KP'
} ump~)?_B
input.close(); KT(Z #$
} @yaFN>w
catch(IOException e){e.printStackTrace ();} kW g.-$pp
catch(Exception e){e.printStackTrace ();} (8JU!lin
} @0?!bua_|
>0IZ%Wiz
u#E'k KGO
private void processErrorCode(int nErrorCode) pSw/QO9
{ v~P,OP("c
System.err.println("Error Code : " + nErrorCode); o|(5Sr&H
} %X{EupiFA
@Iv;y*y
$RPW/Lyiq
//停止文件下载 }~XWtWbd-
public void siteStop() V0\[|E;F
{ HgF;[rq3Q
bStop = true; >M,oyM"s
for(int i=0;i<nStartPos.length;i++) $RaN@& Wm
fileSplitterFetch.splitterStop(); )|F|\6:ne
+$,Re.WnP
h4?x_"V"
} FRBu8WW0L
} n{;j
//负责部分文件的抓取 'x!\pE-
**FileSplitterFetch.java !Lf<hS^
*/ V)`2Kw
package NetFox; IY`p7 )#i
x<NPp&GE
@c3xUK
import java.io.*; &_ekA44E
import java.net.*; SAx9cjj+
]k0 jmE
x *eU~e_jP
public class FileSplitterFetch extends Thread { ,fVD`RR(W?
p T(M>LP83
Lx^ eaP5
String sURL; //File URL /U~|B.z@6
long nStartPos; //File Snippet Start Position #<im?
long nEndPos; //File Snippet End Position 6[> lzEZ
int nThreadID; //Thread's ID X*8y"~X|vq
boolean bDownOver = false; //Downing is over %qP[+N&
boolean bStop = false; //Stop identical )h!cOEt
FileAccessI fileAccessI = null; //File Access interface ISbs l=F
&],uD3:5O
=!O->C:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kmI0V[Y
{ q+ $6D;9
this.sURL = sURL; yB*,)x0 @
this.nStartPos = nStart; FK|O^->B
this.nEndPos = nEnd; `2s!%/
nThreadID = id; `FP?9R6Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WNjwv/
} mPV<a&U
kSQ8kU_w+
'|C3t!H`
public void run() ly[LF1t
{ X%1TsCKMj
while(nStartPos < nEndPos && !bStop) )D)5 `n)
{ ^QB[;g.O
D6sw"V#
p*Bty@CRi
try{ hRcb}>pr
URL url = new URL(sURL); 7|P kc(O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U@lc1#
httpConnection.setRequestProperty("User-Agent","NetFox"); NR{wq|"
String sProperty = "bytes="+nStartPos+"-"; l\HdB"nT
httpConnection.setRequestProperty("RANGE",sProperty); aER|5!7(2\
Utility.log(sProperty); mP(3[a_Q
@fL ^I&++
OZ,kz2SF#
InputStream input = httpConnection.getInputStream(); Hd|l6/[xz
//logResponseHead(httpConnection); p5Q]/DhG
f^WTsh]
KhCP9(A=Qo
byte[] b = new byte[1024]; v<qh;2
int nRead; (L_-!=e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !d*[QD8
{ IP~!E_e}\
nStartPos += fileAccessI.write(b,0,nRead); ^4y]7p
//if(nThreadID == 1) ;SR ESW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); US6_5>/
} 092t6D}
R$a<=
\INH[X#>
Utility.log("Thread " + nThreadID + " is over!"); !QUY (
bDownOver = true; j=_rUc'Me
//nPos = fileAccessI.write (b,0,nRead); Q M,!-~t
} &K)8
catch(Exception e){e.printStackTrace ();} weitDr6
} )Nv1_en<!
} VSj!Gm0LB
~xH&"1
!XA3G`}p6s
//打印回应的头信息 7p&jSOY
public void logResponseHead(HttpURLConnection con) XX;4A
{ 30Yis_l2h
for(int i=1;;i++) bdUPo+
{ "}]`64?
String header=con.getHeaderFieldKey(i); )^h6'h`
if(header!=null) cH]tZ$E`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dn6B43w
Utility.log(header+" : "+con.getHeaderField(header)); KWwtL"3
else T X`X5j
break; xS18t="
} 3:%k pnO
} jjpYg
*OVB;]D3+
6Z/`p~e
public void splitterStop() ;`9f<d#\
{ 1C[9}}
bStop = true; y!e]bvN
} <G"cgN#]
bRC243]g*A
#%"q0"
} 4p_C+4
&[.5@sv
(iIw}f)w
/* 'Pz%c}hJ
**FileAccess.java T?9D?u?]
*//文件访问(定位，写) idmU.`
package NetFox; QbU5FPiN
import java.io.*; B( [x8A]
eh#37*-
D{|qP nE4
public class FileAccessI implements Serializable{ E3L?6Qfx>
I8F+Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]!UYl
RandomAccessFile oSavedFile; ~iw&^p|=K
long nPos; rvA>khu0/
gmTBT#{6yH
wZrFu(_
public FileAccessI() throws IOException xQ?>72grP
{ !`ol&QQ#
this("",0); 1I Yip\:lS
} Pms@!yce
^<]'?4m]
[^>XRBSm
public FileAccessI(String sName,long nPos) throws IOException a"~o'W7
{ _8K+iqMZG
oSavedFile = new RandomAccessFile(sName,"rw"); y48]|%73
this.nPos = nPos; a|ftl&uk
oSavedFile.seek(nPos); KaIKb=4L|
} V>$( N/1
owVvbC2<b(
H$6RDMU
public synchronized int write(byte[] b,int nStart,int nLen) wNONh`b
{ ,'NasL8?We
int n = -1; .^YxhUH,G
try{ p_r`"
oSavedFile.write(b,nStart,nLen); $QX$rN
n = nLen; @xG&K{j
} ?7{U=1gb$
catch(IOException e) 5Z=4%P*I
{ f^%3zWp|-
e.printStackTrace (); PSrx!
} &\zYbGU
F<4rn
;w{<1NH2+.
return n; `CK~x=
} M,Gy.ivz
:XKYfc_y
~G@NWF?7
} [%IOB/{N
Ht`fC|E
/iW+<@Mas
/* ]kh]l8t^
**SiteInfoBean.java Rq4;{a/j
*/ >Wg= Tuef
package NetFox; Y#U.9>h
9t! d.}
?2<QoS
public class SiteInfoBean { ",r v%i2 f
G hM
#h!+b
private String sSiteURL; //Site's URL c '|*{%<e2
private String sFilePath; //Saved File's Path |jsI-?%8J
private String sFileName; //Saved File's Name ktu?-?#0,
private int nSplitter; //Count of Splited Downloading File kuY^o,u-1e
YMGy-]!o
X<ex >sM
public SiteInfoBean() ;W|kc</R*
{//nSplitter的缺省值为5 UhB+c
//default value of nSplitter is 5 ?7\V)$00(&
this("","","",5); 1=VyD<dNG6
} xBHf~:!
PZ[-a-p40
xL* psj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b[%@3}E
{ ci,(]T+!
sSiteURL= sURL; $`pf!b2Z
sFilePath = sPath; UBo0c?,4
sFileName = sName; S)CsH1Q
this.nSplitter = nSpiltter; }2 S.
HG]ARgOB
FlO?E3d
} O[X*F2LC4
:@w~*eK~
:J;U~emq
public String getSSiteURL() 8)B{x[?|
{ F`}'^>
return sSiteURL; )! [B(
} #83
@kXuC<
=dm9+ff
public void setSSiteURL(String value) 3j#VKj+Uc
{ H4i}gdR
sSiteURL = value; N$=YL @m8
} 4+olyBht
L3]J8oEmU
^&3vGu9
public String getSFilePath() tqZ91QpW
{ z/Lb1ND8
return sFilePath; 88Pt"[{1
} hV3]1E21"
]4rmQAS7"
Q`CuZkP(
public void setSFilePath(String value) 3G// _f
{ b[vE!lJEq
sFilePath = value; Rtf<UhUn
} u5CSx'h]
I0-1Hr
Kq7r+A
public String getSFileName() L5hF-Ek! 3
{ NF$6yv9C
return sFileName; %Tp9GGt
} #rHMf%0
OPvPP>0*8
@`.4"*@M
public void setSFileName(String value) 0+&WIs
{ DksYKv
sFileName = value; UG vIHm
} Uo3
=B&|\2`{)
r$<!?Z
public int getNSplitter() -J]?M
{ 0GMb?/
return nSplitter; }3 /io0"D
} J~x]~}V&
t!D'ZLw
rpk8
public void setNSplitter(int nCount) St;9&A
{ M]8>5Zx.
nSplitter = nCount; AB=%yM7V*
} `n+uA~
} !&%KJS6p4
pI@71~|R
l6zAMyau5
/* 9WHE4'Sa
**Utility.java l4gH]!/@
*/ q\tr&@4iC
package NetFox; /OKp(u;)z
+kI}O*s
6>?qBWW
public class Utility { qMaO1cE\
za>%hZf\
P, x"![6
public Utility() |E13W
{ k(f),_
+5fB?0D;
F%L"Q>aHW
} Eu|/pH=:
fMwF|;
//线程睡眠 lB}?ey
public static void sleep(int nSecond) s.(.OXD&
{ y9}qB:[bR
try{ f y|JE9Io_
Thread.sleep(nSecond); 4n#u?)
} H Qj,0#J)
catch(Exception e) y^r'4zN'
{ X&Oo[Z
e.printStackTrace (); ?`TQ!m6y
} o.$48h(
} .p{lzI9
h`Jc%6o
//日志 <mX5VGY9^
public static void log(String sMsg) J rK{MhO
{ dC<%D'L*
System.err.println(sMsg); h5{//0 y
} >MJ%6A>
hMupQDv/I
{F_>cyR
public static void log(int sMsg) d{TcjZ
{ E[hSL#0
System.err.println(sMsg); /A5=L<T6F
} }51QUFhL0
} ^uo,LTq+
padV|hF3(e
YBY;$&9
/* 6cg,L:j#
**TestMethod.java 9u~C?w
*/ L^u|=9
package NetFox; ?23J(;)s
)^UqB0C6^
dLQp"vs$
public class TestMethod { A?tCa*b^
0MT?}D&TL
,%Pn.E* r;
public TestMethod() TaF*ZT2
{ ///xx/weblogic60b2_win.exe +;H=_~b
try{ `-nSH)GBM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bSM|"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {? yRO]
SiteFileFetch fileFetch = new SiteFileFetch(bean); C\rT'!Uk\Q
fileFetch.start(); ZyDf@(z`
} ;8VZsh
catch(Exception e){e.printStackTrace ();} `?:{aOI
[/ CB1//Y
va~:Ivl-)
} 0r@LA|P
3{H!B&sb
5i$P$ R
public static void main(String[] args) x8z6 <
{ 0?R$>=u
new TestMethod(); /3+E-|4s
} *{JD=ua
} =5:vKL j
点击下载更多相关资料