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)); m2 OP=z@)
} Ot/Y?=j~
for(int i=0;i<nEndPos.length-1;i++) ]zD/W%c
{ <;acWT?(
nEndPos = nStartPos[i+1]; 2Gx&ECa,
} #$#{QEh0}
nEndPos[nEndPos.length-1] = nFileLength; mDo]5 i<
} ?B[Z9Ef"8l
} / P{f#rV5
/.}&yRR
)ll}hGS
//启动子线程 MEo+S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ib!`ChZ
for(int i=0;i<nStartPos.length;i++) } #$Y^ +UN
{ (D))?jnC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^%C.S :
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), []u!piW
nStartPos,nEndPos,i); ,.E:mm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3J@#V '
fileSplitterFetch.start(); :k JSu{p
} ) I@gy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AU)Qk$c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y/Nvts2!C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z|3l2ucl
nEndPos = " + nFileLength); bluC P|
// fileSplitterFetch[nPos.length-1].start(); kR'!;}s
C YnBZ
rYc?y
//等待子线程结束 lKe aI
//int count = 0; o6svSS
//是否结束while循环 U-|gtND
boolean breakWhile = false; Yr[1-Oy/k
t6j(9[gGq
hNP|
while(!bStop) D?9=q
{ %1e`R*I
write_nPos(); K34y3i_
Utility.sleep(500); bu\,2t}B
breakWhile = true; )0/DY
`<[Zs]Fe4
%M ~X:A;4
for(int i=0;i<nStartPos.length;i++) ,A_itRHH
{ G;,2cu K
if(!fileSplitterFetch.bDownOver) kigc+R
{ qk<tLvD_'
breakWhile = false; ZLBfQ+pM)
break; _:=w6jCk
} [7L1y) I(
} ?EKYKLwr
if(breakWhile) ynDa4HB
break; '0w'||#1
$] w&`F-
eK`n5Z&Y\
//count++; ,TP^i 0
//if(count>4) @{~x:P5g
// siteStop(); ~D 5'O^
} _RhCVoeB
u9'4q<>&
)|\72Z~eq
System.err.println("文件下载结束！"); Lv#DIQ8y
} 44wY5nYNt
catch(Exception e){e.printStackTrace ();} :0#!=
} eF:6k qg
pH)V:BmJ
8`'_ckIgr
//获得文件长度 |1;0q<Ka
public long getFileSize() dZv-lMYBE
{ 6rdm=8WFA
int nFileLength = -1; }LQ&AIRN
try{ .rax`@\8
URL url = new URL(siteInfoBean.getSSiteURL()); \'j%q\Bl;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); llQDZ}T
httpConnection.setRequestProperty("User-Agent","NetFox"); kg+"Ta[9
>m%\SuXq
H6*F?a`)I
int responseCode=httpConnection.getResponseCode(); ;J2=6np
if(responseCode>=400) }1epn#O_4
{ v-&^G3
processErrorCode(responseCode); Zj!S('hSY
return -2; //-2 represent access is error &eyFApM[Z
} Rl<~:,D
~(G]-__B<
f+J<sk
String sHeader; /.Gx n0
_ ?=bW
q'{E $V)E
for(int i=1;;i++) ${mHbqN
{ $wC]S4C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wGAN"K:e
//Utility.log(in.readLine()); /ijj;9EB
sHeader=httpConnection.getHeaderFieldKey(i); oP_'0h0X
if(sHeader!=null) e)>Z&e,3
{ 0Tg/R4dI
if(sHeader.equals("Content-Length")) sd.:PE <
{ +-`Q}~s+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rVFAwbR
break; e2Ba@e-
} swe6AQ-
} X1y1
else W<v?D6dFq
break; JrS/"QSA
} M HlP)'
} q<.^DO~$L
catch(IOException e){e.printStackTrace ();} (9@6M8A
catch(Exception e){e.printStackTrace ();} 1%EIP-z
A]ciox$AjW
) Q]kUG#`
Utility.log(nFileLength); Ku56TH!Py
js'*:*7
Xpjk2[,
return nFileLength; 0.bmVN<
} B1J+`R3OX
x^9W<
fHR1kuy
//保存下载信息（文件指针位置） w,9$*=k
private void write_nPos() X62z>mM
{ + ECV|mkk
try{ qEX59v
output = new DataOutputStream(new FileOutputStream(tmpFile)); }=;N3Q" #y
output.writeInt(nStartPos.length); s%;18V:pi
for(int i=0;i<nStartPos.length;i++) x>p=1(L
{ jHTaG%oh
// output.writeLong(nPos); s XRiUDP`
output.writeLong(fileSplitterFetch.nStartPos); C`7HC2Is
output.writeLong(fileSplitterFetch.nEndPos); 6HFA2~A
} bG;vl;C
output.close(); l*xA5ObV
} $Y)|&,
catch(IOException e){e.printStackTrace ();} Xq+7l5LP
catch(Exception e){e.printStackTrace ();} ,k+jx53XV
} _N0x&9S$
H\8.T:>
4- N>#
//读取保存的下载信息（文件指针位置） ^FF{71;
private void read_nPos() jZe]zdml
{ p"JITH:G
try{ QWxCNt:^?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cSoZq4
int nCount = input.readInt(); k;l^wM
nStartPos = new long[nCount]; &3S;5{7_e
nEndPos = new long[nCount]; <o^mQq&
for(int i=0;i<nStartPos.length;i++) OA&NWAm4
{ ?^5W.`Y2i
nStartPos = input.readLong(); 9O~1o?ni
nEndPos = input.readLong(); D?8t'3no
} 5"]PwC
input.close(); ~+V]MT
} y/4 4((O
catch(IOException e){e.printStackTrace ();} >c8zMd
catch(Exception e){e.printStackTrace ();} VBBqoyP h
} ;x|4Tm
Js'COO
l?Bv9k.^?
private void processErrorCode(int nErrorCode) "JbFbcj
{ :G$NQ*(z
System.err.println("Error Code : " + nErrorCode); l{_>?]S5
} Pg|q{fc
;{j:5+'
K\,&wU
//停止文件下载 O/iew3YF
public void siteStop() Xj?j1R>GB
{ 0ot=BlMu
bStop = true; 6(<AuhFu
for(int i=0;i<nStartPos.length;i++) C `k^So)
fileSplitterFetch.splitterStop(); s[8<@I*u
/!d,f4n
<),FI <~
} h&;\
} fb&K.6"
//负责部分文件的抓取 +SZ#s:#SE
**FileSplitterFetch.java OKxPf]~4E
*/ ?Ju=L|
package NetFox; xBR2tDi%
v=iz*2+X
(:vY:-\ bO
import java.io.*; w9H%u0V?
import java.net.*; 3Akb|r
DyYl97+Z?
J:5%ff~r\
public class FileSplitterFetch extends Thread { >c;qIP)Z
J$]d%p_I
W(a=ev2sa
String sURL; //File URL oRmN|d ~4
long nStartPos; //File Snippet Start Position F~)xZN3=
long nEndPos; //File Snippet End Position qf(!3
int nThreadID; //Thread's ID G{YJ(6etZ
boolean bDownOver = false; //Downing is over Bn-%).-ED
boolean bStop = false; //Stop identical Zb<DgJ=3
FileAccessI fileAccessI = null; //File Access interface SN\;&(?G
D@7\Fg
yrE|cH'f0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )I$_wB!UV
{ JG0TbM1(Bt
this.sURL = sURL; 9Z6O{ >
this.nStartPos = nStart; GriL< =?t
this.nEndPos = nEnd; ^mkplp a
nThreadID = id; ! FhN(L[=j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HVh+Zk
} mY |$=n5X
~,m6g&>R
%(,JBa:G
public void run() Z\4l+.R`
{ s{Ryh.IyI
while(nStartPos < nEndPos && !bStop) Y]^[|e8
{ 57%:0loW
wvBJ?t,
!H~G_?Mf\O
try{ Q~te`
URL url = new URL(sURL); [1G4he%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DLJu%5F
httpConnection.setRequestProperty("User-Agent","NetFox"); rP^2MH"
String sProperty = "bytes="+nStartPos+"-"; k%VV(P]sT
httpConnection.setRequestProperty("RANGE",sProperty); 0 \&4?
Utility.log(sProperty); vb\UP&Ip
drNfFx2
[gqV}Y"Md
InputStream input = httpConnection.getInputStream(); <eQS16
//logResponseHead(httpConnection); P0 hC4Sxf
GyRU/0'BME
"qMd%RP
byte[] b = new byte[1024]; Y GvtG U-
int nRead; $l7 <j_C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *=UEx0_!q
{ OiJ1&Fz(
nStartPos += fileAccessI.write(b,0,nRead); &5~bJ]P
//if(nThreadID == 1) ,K,n{3]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JY4 +MApN
} QEm6#y
AQ'~EbH(
#e{l:!uS\
Utility.log("Thread " + nThreadID + " is over!"); bCy.S.`jHQ
bDownOver = true; o3qBRT0[R
//nPos = fileAccessI.write (b,0,nRead); P)7SK&]r;=
} P9SyQbcK
catch(Exception e){e.printStackTrace ();} A@f`g[q
} xCiY jl$
} rcY[jF
NcwZ_*sqj
W7_X=>l
//打印回应的头信息 " q0lh
public void logResponseHead(HttpURLConnection con) j2k,)MHu!x
{ QUH USDT
for(int i=1;;i++) <t.yn\G-w
{ m!tB;:6
String header=con.getHeaderFieldKey(i); Go=MG:`
if(header!=null) 3l-8TR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <;=?~QK%-
Utility.log(header+" : "+con.getHeaderField(header)); QZYD;&iY&
else p*8=($j4
break; -'*B%yy
} N0vr>e`
} K*d+pImrV
Vyf r>pgW1
G ZDyw9
public void splitterStop() LW{7|g
{ 9V9K3xWn
bStop = true; _RST[B.u6
} zL+jlUkE
!w(J]<
gC> A*~J;
} Cz#0Gh>1
xKv\z1ra
,KdDowc
/* 4`7N}$j#,
**FileAccess.java dNUi|IYm$
*//文件访问(定位，写) p?>(y
package NetFox; }} J?, >g
import java.io.*; +>M^p2l*&
LD0x 4zm$m
.Wc<(pfa
public class FileAccessI implements Serializable{ ~+/IzckrG
U_K"JOZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .!/DM-C
RandomAccessFile oSavedFile; wzwEYZN(q
long nPos; NhU~'k
h.l^f>,/
[U5[;BNRD
public FileAccessI() throws IOException !9_HZ(W&
{ HQCxO?
this("",0); g=XvqD<
} yT.h[yv"w
-Wd2FD^x
&CpxD."8x
public FileAccessI(String sName,long nPos) throws IOException G%jgr"]\z
{ Hbn%CdDk1
oSavedFile = new RandomAccessFile(sName,"rw"); nm`[\3R
this.nPos = nPos; ?\"GT]5D
oSavedFile.seek(nPos); _zvCc%
} %@k@tD6
PzMJ^H{
m(i84~
public synchronized int write(byte[] b,int nStart,int nLen) o^&u?F9
{ Qz=F nR
int n = -1; xQ+UZc
try{ X ^8@T
oSavedFile.write(b,nStart,nLen); ^~9fQJNs
n = nLen; BKvX,[R2
} zo6|1xq
catch(IOException e) z$4g9
{ ,R#pQ 4
e.printStackTrace (); 8Wqh 8$
} ?<)4_
Q3[MzIk 4
=(2y$,6g?
return n; )S@e&a|
} +pXYBwH 7Q
|;sL*Vr
f>!)y-7
} c<bV3,
kw{dvE\K
1y'8bt~7Pf
/* C~-x637/
**SiteInfoBean.java ]9qY(m
*/ js;p7wi
package NetFox; o@:${>jw
Heh.CD)Q
xY4g2Q J
public class SiteInfoBean { @+Yql
SQ'\Kd=
~tx|C3A`d
private String sSiteURL; //Site's URL E)sC:oO
private String sFilePath; //Saved File's Path J=7.-R|t
private String sFileName; //Saved File's Name h K;9XJAf
private int nSplitter; //Count of Splited Downloading File -LzkM"
\A7{kI
)l?1dR:sP
public SiteInfoBean() 2tD{c^ 9<
{//nSplitter的缺省值为5 jV{?.0/h|
//default value of nSplitter is 5 |?v(?
this("","","",5); !z?&
} Voy1
~&HP}Q$#f
yX9 .yq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X})5XYvA*
{ S:B$c>
sSiteURL= sURL; )|3BS`
sFilePath = sPath; Y*VF1M,2_
sFileName = sName; k_;g-r,
this.nSplitter = nSpiltter; 4g4[n7
>AK9F. _z
)j,Y(V$P
} $, hHR:
zUuOX5-6x
gGZ-B<
public String getSSiteURL() ;k?Z,M:
{ 'Em3;`/C*+
return sSiteURL; VAW:h5j2@
} r&%TKm^/
f$>KTb({B
M.FY4~
public void setSSiteURL(String value) 90wGS_P04
{ :j2?v(jT_l
sSiteURL = value; 21k,{FB'?
} =/5^/vwgY
hY5GNYDh
5Ve`j,`=<
public String getSFilePath() hGU m7
{ *kYJwO^
return sFilePath; TWSqn'<E
} cMs8D
ygK@\JHn
3vXa#f>P<
public void setSFilePath(String value) rEHlo[7^
{ Bnp\G h
sFilePath = value; Qm_IU!b
} L"KKW c
3</W}]$)p
M^ZEAZi
public String getSFileName() p40;@gUug
{ *@I/TX'\rY
return sFileName; C5Vlqc;
} d`gKF
aD^jlt
NufRd/q
public void setSFileName(String value) ="p,~ivrz
{ aT4I sPA?_
sFileName = value; t|urvoz
} ~6A;H$dr
Sw.k,p*r
!C(U9p. 0
public int getNSplitter() ^jbjHI&
{ #<K'RJn
return nSplitter; LpK? C<?x
} >P+oNY
)O],$\u
' !2NSv
public void setNSplitter(int nCount) \@[Y~:
{ buldA5*!o
nSplitter = nCount; R]&lVXyH
} s%QCdU ]
} tWyl&,3?1
E4$y|Ni"
!J&UO/q.
/* IG.!M@_
**Utility.java HTLS$o;Q
*/ 0"}=A,o(w
package NetFox; D&o~4Qvc]
J#IVu?B
z6*r<>Bf+b
public class Utility { ^ Paf-/
B&QEt[=s
b*(,W
public Utility() ,. zHG
{ C2CR#b=)i
{[4.<|26
Up1n0
} 5dX /<
8d?%9# p-)
//线程睡眠 [Kg3:]2A
public static void sleep(int nSecond) C);3GPp
{ 2KlVj]!7
try{ "8p<NsU
Thread.sleep(nSecond); >Hu3Guik]
} B)*1[Jf{4
catch(Exception e) :9DyABK=Cv
{ \JC_"gqt
e.printStackTrace (); 2g~W})e
} `PZ\3SC'i
} 4/V;g%0uN;
TNDp{!<|L;
//日志 Q@"}v_r4
public static void log(String sMsg) )<%CI#s#
{ ^-LnO%h?
System.err.println(sMsg); n&!q9CR`
} ~Ede5Vg!!2
#@' B\!<@=
JXjH}C
public static void log(int sMsg) ^RE[5h6^q
{ L&KL]n
System.err.println(sMsg); P2&0bNY
} HVdB*QEH
} xS(VgP&YGO
D9 Mst6
~W-l|-eogz
/* f%3MDI
**TestMethod.java /2''EF';
*/ 1,Es'
package NetFox; Ey.%: O-Dv
KjMwrMgC
n<P&|RTZ
public class TestMethod { R, #szTu
8`s*+.LI!
_%3p&1ld
public TestMethod() XqU0AbQ
{ ///xx/weblogic60b2_win.exe FJqg,
try{ Sz:PeUr9h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +f$ {r7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); guVuO
SiteFileFetch fileFetch = new SiteFileFetch(bean); pHowioFx
fileFetch.start(); gL~3z'$
} TV|Z$,6l
catch(Exception e){e.printStackTrace ();} ^F qs,^~W
H?eG5
~1XC5.*-
} Ga+Cb2$
(/^?$~m"
i1X!G|Awfv
public static void main(String[] args) L8f_^ *,
{ D-D8La?0p
new TestMethod(); ]yQqx*
} tSY4'
} \vx'+}
点击下载更多相关资料