http断点续传简单实现（java)

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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)); S7a6ntei
} u mlZ(??.
for(int i=0;i<nEndPos.length-1;i++) pU]{Z(
{ @6q$Zg/
nEndPos = nStartPos[i+1]; ? ~Zrd
} F?} *ovy
nEndPos[nEndPos.length-1] = nFileLength; 8uxFXQ
} Z5Ihc%J^
} RuNH (>Eb
#`4^zU)
~{YgM/c|dt
//启动子线程 MNqyEc""
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #L.}CzAz
for(int i=0;i<nStartPos.length;i++) eH955[fVd4
{ ?ev G=S4>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +)JqEwCrq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pMp9O/u%
nStartPos,nEndPos,i); W<91m*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j{R|]SjW2H
fileSplitterFetch.start(); ^3|$wB=
} WlQ=CRY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~cBc&u:"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~e<'t4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #}7m'F
nEndPos = " + nFileLength); |D`b7h
// fileSplitterFetch[nPos.length-1].start(); z%3"d0
Qz)8eIO:
DUKmwKM"k
//等待子线程结束 %4|}&,%%r
//int count = 0; pZ~>l=-
//是否结束while循环 ?VZXJO{^
boolean breakWhile = false; _@pf1d$
sq(Ar(L<
X,EYa>RSy_
while(!bStop) liw 9:@+V
{ gQd=0"MV
write_nPos(); `V):V4!j),
Utility.sleep(500); w+9C/U;|s
breakWhile = true; &iiK ZZ`_o
cw]>a&d
;=VK_3"
for(int i=0;i<nStartPos.length;i++) =R;1vUio
{ *_/eAi/WG
if(!fileSplitterFetch.bDownOver) 4a.e ,gitf
{ m)|.:sj
breakWhile = false; O4d^ig-xaH
break; zHoO?tGf
} z?uQlm*We
} $F@L$&~
if(breakWhile) w4fJ`,
break; ds$\vSd
4R*<WdT(
zGL<m0C
//count++; N<Z)b!o%u
//if(count>4) U~#^ ^
// siteStop(); _/%]:
} @@{_[ir
]i,Mq
`YmI'
System.err.println("文件下载结束！"); vi!r8k
} H&yFSz}6a
catch(Exception e){e.printStackTrace ();} dy6F+V\DG
} ^I'Lw
j^$3vj5E[
!: EW21m
//获得文件长度 xU13fl
public long getFileSize() kJ#[UCqzM
{ qSC~^N`
int nFileLength = -1; zN)|g
try{ q(&^9"
URL url = new URL(siteInfoBean.getSSiteURL()); #}t1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *<.WL"Qhl
httpConnection.setRequestProperty("User-Agent","NetFox"); ??\*D9rCn
."F'5eTT~
^aD/ .
int responseCode=httpConnection.getResponseCode(); ^Z-.[Y
if(responseCode>=400) 3<jAp#bE
{ S4k^&$;
processErrorCode(responseCode); :@QK}qFP
return -2; //-2 represent access is error h$aew63
} TRySl5jx@
e}?1T7NPG]
XC7Ty'#"KX
String sHeader; *,pZ fc
XUQW;H
s.p1L
for(int i=1;;i++) 5Aa31"43n
{ hyk|+z`B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MfNpQ:]c\
//Utility.log(in.readLine()); a9? v\hG
sHeader=httpConnection.getHeaderFieldKey(i); j1;_w
if(sHeader!=null) EU^}NZW&v:
{ M\\e e3Ih
if(sHeader.equals("Content-Length")) r}_Lb.1]
{ IFC%%It5,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XQ0#0<
break; Qr|N)
} C;d|\[7Z
} y"|K |QT
else >}dTO/
break; #514a(6
} v2M"b?Q
} e?^\r)1
catch(IOException e){e.printStackTrace ();} HQ|o%9~
catch(Exception e){e.printStackTrace ();} HO%E-5b9
G|QUujl
5';/@M
Utility.log(nFileLength); ~8H&m,{j
LaIW,+
Eu`2w%qz
return nFileLength; BB2_J=wA
} xQNw&'|UU
tsTR2+GZS
DrF
//保存下载信息（文件指针位置） VZT6;1TD$8
private void write_nPos() ~ V@xu{
{ :DOr!PNA
try{ {f`lSu
output = new DataOutputStream(new FileOutputStream(tmpFile)); [+hy_Nc$
output.writeInt(nStartPos.length); H$NP1^5!
for(int i=0;i<nStartPos.length;i++) GN:Ru|n
{ +8LM~voB
// output.writeLong(nPos); Pcs^@QP
output.writeLong(fileSplitterFetch.nStartPos); wFK:Dp_^
output.writeLong(fileSplitterFetch.nEndPos); CTh1+&Pa
} \]Y\P~n
output.close(); 0OleO9Ua
} WW@JVZxK
catch(IOException e){e.printStackTrace ();} 3+CSQb8
catch(Exception e){e.printStackTrace ();} 6V'wQqJ
} %/{IssCR7
Y5nz?a
#5'c\\?Q
//读取保存的下载信息（文件指针位置） =]=B}L`
private void read_nPos() ??%)|nj.
{ X4d Xm>*?=
try{ bin6i2b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J}x>~?W
int nCount = input.readInt(); 7[ZkM+z!
nStartPos = new long[nCount]; sx-EA&5-9k
nEndPos = new long[nCount]; th5,HO~
for(int i=0;i<nStartPos.length;i++) n?y'c^
{ m(2G*}
nStartPos = input.readLong(); L_tjcfVo
nEndPos = input.readLong(); z[WC7hvU
} 5."5IjZu
input.close(); ]XmQ]Yit
} zt7_r`#z
catch(IOException e){e.printStackTrace ();} v*&Uk'4E
catch(Exception e){e.printStackTrace ();} ^{),+S
} 9uuta4&uI
Ya~ "R#Uy
* eA{[
private void processErrorCode(int nErrorCode) =YWT|%^uX
{ U5|B9%:&
System.err.println("Error Code : " + nErrorCode); +2- qlU
} Bx+d3
A|2 <A !
)J;ny!^2
//停止文件下载 6,B-:{{e"
public void siteStop() smQ4CLJ
{ N2ni3M5v
bStop = true; f_oq1W)9
for(int i=0;i<nStartPos.length;i++) ZH\0=l)
fileSplitterFetch.splitterStop(); cN62M=**
Hr(6TLNw
5i|s>pD4z1
} DNmb[
} Vre=%bGw
//负责部分文件的抓取 VK9Q?nu
**FileSplitterFetch.java Kl2}o|b
*/ :qBGe1Sv(
package NetFox; 9H>BWjS
+-U@0&Y3M
p=2zS.
import java.io.*; R|-6o)$
import java.net.*; {z=j_;<]
P= e4lF.
]Qd{ '}+
public class FileSplitterFetch extends Thread { b9`iZ
5bXHz5i
F{;; :
String sURL; //File URL Bw6L;Vu
long nStartPos; //File Snippet Start Position Hc M~
long nEndPos; //File Snippet End Position kQy&I3
int nThreadID; //Thread's ID JfbKf~g
boolean bDownOver = false; //Downing is over D@#0dDT
boolean bStop = false; //Stop identical z*RSMfRW
FileAccessI fileAccessI = null; //File Access interface c& 3#-DNI
F,Q?s9s
/oFc03d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #Gd7M3
{ ("OAPr\2dw
this.sURL = sURL; GYd]5`ri
this.nStartPos = nStart; eI0F!Yon
this.nEndPos = nEnd; h20Hg|
nThreadID = id; mGO>""<:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ujx@@N
} +tIz[+u
3524m#4&@
:\mRtVH
public void run() _PV*lK=
{ _|X7 n~
while(nStartPos < nEndPos && !bStop) G,=F<TnI'
{ Z2#`}GI_m
3?@?-q2g
Z^*NnL.'
try{ Y87XLvig}
URL url = new URL(sURL); {c@G$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }a^|L"
httpConnection.setRequestProperty("User-Agent","NetFox"); qi&D+~Gv!
String sProperty = "bytes="+nStartPos+"-"; 8aZ$5^z
httpConnection.setRequestProperty("RANGE",sProperty); N 'i,>
Utility.log(sProperty); ;\x~'@
nkRK+~>
LQqfi ~
InputStream input = httpConnection.getInputStream(); (UGol[f<
//logResponseHead(httpConnection); 3{e'YD~hP
#]y5zi
@cIgxp
byte[] b = new byte[1024]; ' S,2
int nRead; w.uK?A>W,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U(*yL-
{ %'0&ElQ
nStartPos += fileAccessI.write(b,0,nRead); =!CU $g
//if(nThreadID == 1) t8/%Dgu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bc<n2 C0
} @VK6JjIq
88l,&2q
OJpj}R
Utility.log("Thread " + nThreadID + " is over!"); 8teJ*sz
bDownOver = true; G6Nb{m
//nPos = fileAccessI.write (b,0,nRead); #tDW!Xv?
} Kam]Mn'
catch(Exception e){e.printStackTrace ();} YE\K<T jH
} 1TZPef^y
} 0x~`5h
NR3`M?Hjf
DP*@dFU"
//打印回应的头信息 XYAmJ
public void logResponseHead(HttpURLConnection con) rwgsXS8W6
{ "hPCQp`Tj
for(int i=1;;i++) V!&P(YO:
{ Qxt@V
String header=con.getHeaderFieldKey(i); -DCa
if(header!=null) ,{KCY[}|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q7GY3X*kA
Utility.log(header+" : "+con.getHeaderField(header)); !d8A
else p`P~i&_
break; 6(KmA-!b(O
} EB,4PEe:
} af'@h:
{Uq:Xw
0^&!6R
public void splitterStop() fu]N""~
{ 9Cvn6{
bStop = true; o`6|ba
} O+"ac /r
:(p)1=I
E FY@Y[
} &=Y e6 f[
h{_*oBa
j@| `f((4
/* Ik~1:D]f
**FileAccess.java "HlgRp]u
*//文件访问(定位，写) 'jjb[{g^}}
package NetFox; ][7p+IsB
import java.io.*; >]?H`>4(
=k{`oO~:9+
GwLFL.Ke
public class FileAccessI implements Serializable{ ]KuMz p!
o2uj =Gnx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xy7Z38G
RandomAccessFile oSavedFile; P8I*dvu _
long nPos; n]N96oD
YnTB&GPxl
e@n!x}t8
public FileAccessI() throws IOException KnzsHli,~k
{ >M;u*Go`QO
this("",0); Cifd21v4
} _[K#O,D,
1*Ar{:+ua
n&Yk<
public FileAccessI(String sName,long nPos) throws IOException #T3h}=
{ XDz5b.,
oSavedFile = new RandomAccessFile(sName,"rw"); %XTA;lrz
this.nPos = nPos; Z|*!y]We
oSavedFile.seek(nPos); :c]`D>
} pq!%?m]
RBGX_v?
z@VP:au
public synchronized int write(byte[] b,int nStart,int nLen) G/?~\ }:s
{ vqNsZ 8|`
int n = -1; m~`>`4
try{ Is.WZYa
oSavedFile.write(b,nStart,nLen); *}!MOqP
n = nLen; [QczlwmO
} K%j&/T j1
catch(IOException e) Q^_/By@
{ 7;}l\VXHm
e.printStackTrace (); kQv*eZ~
} 2eP;[o
xUWr}j4;
, c;eN
return n; NgZUnh3{
} rOfK~g,X
6oL1_)
/^7iZ|>:M:
} ]MTbW=*}ED
5g ;ac~g
&h~aChJ
/* 8v92Ng7
**SiteInfoBean.java [rYT
*/ v3RcwySk
package NetFox; O&Z'r
v."Dnl
/SR^C$h'I
public class SiteInfoBean { (9RslvKL
cma*Dc
F?4(5 K
private String sSiteURL; //Site's URL HAB#pd9
private String sFilePath; //Saved File's Path RDQ^dui
private String sFileName; //Saved File's Name eiMH['X5
private int nSplitter; //Count of Splited Downloading File yJJ4~j){l
*~VxC{
h{iEZ#
public SiteInfoBean() m7|RD]q&
{//nSplitter的缺省值为5 B|{I:[
//default value of nSplitter is 5 ~,gXaw
this("","","",5); % 4 ~l
} L/r@ S'
NucM+r1P
e$/B_o7(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lhLGG
{ !]?$f=
sSiteURL= sURL; 8g/F)~s^F
sFilePath = sPath; *,WP,-0
sFileName = sName; ^y_fRP~
this.nSplitter = nSpiltter; %@J1]E;
I=Zx"'Um
uQCo6"e
} 3`V1XE.;
o4^Fo p
H#d:kilNy
public String getSSiteURL() 12`_;[37
{ C?Zw6M+
return sSiteURL; pxINw>\Qv
} &XLD S=j
*TdnB'Gd
8\ha@&p
public void setSSiteURL(String value) >v5k{Cbp0
{ _%@=Uc6V
sSiteURL = value; dj9?t
} mj,fp2D;%
[w\?j,
n-;y*kD
public String getSFilePath() JC;^--0(z
{ ]dPZ.r
return sFilePath; B5am1y{P#
} )h$NS2B`
H}0dd"
2ef;NC.&n
public void setSFilePath(String value) =([av7
{ PH4%R]{8{
sFilePath = value; 9l/EjF^
} 2(YPz|~W
V9 }t0$LN
-`c:}m
public String getSFileName() &lc8G
{ |BU+:+
return sFileName; 4/>Our 5
} uZ6d35MJ
o@E/r.uK
@Cq? :o<
public void setSFileName(String value) kUHE\L.Y]
{ 5ua?I9fY
sFileName = value; M~T.n)x2
} {==pZpyyh
i^z`"3#LE
B)SLG]72f
public int getNSplitter() }qPhx6nP
{ TJ@Cjy%
return nSplitter; f>Td)s1 M
} ph:3|d
PFSLyV*
h+7>#*DH
public void setNSplitter(int nCount) *=F(KZ
{ qB6dFl\ (
nSplitter = nCount; cSP*f0n,eo
} M++0zhS
} ,%"xH4d
tl8O6`<Z
m 40m<@
/* Y#V8(DTyH
**Utility.java &rq{v!=7
*/ D@Da0
package NetFox; `|e!Kq?#Q
'w/qcD-
h=VqxGC&
public class Utility { #} ,x @]p
nY-* i!H
<EX7WA
public Utility() czWw~'."
{ h,t|V}Wb
"l~Ci7& !a
,32xcj}j)r
} {[G`Z9]z&-
dz9Y}\2tf
//线程睡眠 ;6;H*Y0,|E
public static void sleep(int nSecond) {+T/GBF-K=
{ R'K/t|MC
try{ D>ef
Thread.sleep(nSecond); T.&7sbE_
} (RL>Hn;.
catch(Exception e) mX# "+X|
{ LgqGVh3\s
e.printStackTrace (); *7gT}O;p 5
} h BMH)aU
} !>.vh]8g
I2Ev~!
//日志 Fe=8O ^\
public static void log(String sMsg) D@54QJ<
{ &_-](w`
System.err.println(sMsg); ]?l{j
} HxwlYx,4
*YV S|6bs
>l1r,/\\
public static void log(int sMsg) 0&w0aP`Y
{ Y*YFB|f?
System.err.println(sMsg); ISqfU]>[
} 'ig, ATY
} }uO5q42
m2bDHQ+
U@lV
/* t8J/\f=
**TestMethod.java i.a _C'<$
*/ >.%4~\U
package NetFox; pa/9F[
vs9?+3
;IP~Tb]&
public class TestMethod { ]#eh&jw
5G*II_j
C8b''9t.
public TestMethod() G?)vWM`j
{ ///xx/weblogic60b2_win.exe ;Rnhe_A.
try{ ';YgG<u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T 1Cs>#)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Xf(^K
SiteFileFetch fileFetch = new SiteFileFetch(bean); f6ZZ}lwaV
fileFetch.start(); =Viy^ieN$
} 4('JwZw\!
catch(Exception e){e.printStackTrace ();} sg?@qc=g
Z6s5M{mE
"dCzWFet
} Uene=Q6>
i57( $1.
7sV/_3H+
public static void main(String[] args) Go8F5a@j
{ -F`he=Ev9
new TestMethod(); 9YKDguG
} JeQ[qQ
} 9D_wG\g
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