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)); Tg@G-6u0c
} .Gr"|uII
for(int i=0;i<nEndPos.length-1;i++) 3nhQ^zqf
{ 9({ 9r[U
nEndPos = nStartPos[i+1]; ;6 d-+(@
} )N^fSenFBn
nEndPos[nEndPos.length-1] = nFileLength; {c?{M.R
} ^|h_[>
} 2.);OFk+
7?k3jDK
MTE1\,
//启动子线程 1=+S'_j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *dB3Gu{ +
for(int i=0;i<nStartPos.length;i++) 9b-4BON{P
{ %<Qv?`B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &=%M("IlD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;A"i.:ZT
nStartPos,nEndPos,i); tD}{/`{_t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Y UT*
fileSplitterFetch.start(); QrSO%Rm1*
} h Ks
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wn;%B].I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '^7Z]K<v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mBrZ{hqS
nEndPos = " + nFileLength); h8M}}
// fileSplitterFetch[nPos.length-1].start(); 4>Ht_B<<
H 9/m6F
JT6Be8
//等待子线程结束 `3K."/N6c
//int count = 0; IYptNR
//是否结束while循环 UZiL NKc
boolean breakWhile = false; <uoVGV5N
0.!vp?
874j9ky[
while(!bStop) j";L{
{ e5FF'~A%]
write_nPos(); s;Zi
Utility.sleep(500); 56C'<#
breakWhile = true; _8`S&[E?
P%w!4v~"
M9VAs~&S
for(int i=0;i<nStartPos.length;i++) OHngpe4
{ g p|G q
if(!fileSplitterFetch.bDownOver) z:O:g?A
{ =VWH8w.3
breakWhile = false; 0lqh;/
break; l'!_km0{d
} %dmQmO,
} I L&PN`#
if(breakWhile) E'+z.~+
break; xw~oR|`U
_iqaKYT$
-yIx:*KI
//count++; n]l3 )u
//if(count>4) 7we='L&R
// siteStop(); /8dRql-Ne
} SZxnYVY
HsG3s?*
44^jE{,9
System.err.println("文件下载结束！"); ] :](xW%
} qw|B-lT{:
catch(Exception e){e.printStackTrace ();} ~:0U.v_V
} *&_(kq z'1
0'5N[Bvp
?v+el,
//获得文件长度 s/;S2l$`
public long getFileSize() #cJ1Jj $
{ $G/p[JG6-
int nFileLength = -1; {>ghX_m|
try{ >^@~}]L
URL url = new URL(siteInfoBean.getSSiteURL()); Zwtz )ZII
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HR'F
httpConnection.setRequestProperty("User-Agent","NetFox"); 6_w~#86=
bI;u};v
XaU^^K
int responseCode=httpConnection.getResponseCode(); oC!z+<
if(responseCode>=400) wUS w9xg
{ ncR]@8
processErrorCode(responseCode); Q`=d5Uvw
return -2; //-2 represent access is error \$,;@H5I^
} k_OzkEM9!
1NN#-U
&6\E'bBt
String sHeader; A(C0/|#V
y]k{u\2A
,}^;q58
for(int i=1;;i++) *'@T+$3s
{ ? a*yK8S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N40DL_-
//Utility.log(in.readLine()); 9~r8$,e
sHeader=httpConnection.getHeaderFieldKey(i); `Z@qWB<
if(sHeader!=null) w/ID yQ
{ Jd|E 4h~(
if(sHeader.equals("Content-Length")) <5|:QLqy
{ '_n$xfH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0e'@Xo2e
break; k <LFH(
} 7X/B9Hee
} ;T!ZO@1X
else Z7MGBwP(
break; 0n?^I>j
} +'g~3A-G
} |)ALJJ=+
catch(IOException e){e.printStackTrace ();} 3qp\jh=FE
catch(Exception e){e.printStackTrace ();} v?q)E%5j
p"Di;3!y!
f F9=zrW
Utility.log(nFileLength); Is ( Ji
Ez^wK~
Q"GZh.m
return nFileLength; ML1/1GK*i+
} R8, g^N
m8*)@e
N<HJ}geC"
//保存下载信息（文件指针位置） n--s[Kdo8
private void write_nPos() U,\t2z
{ )3!z2f:e
try{ k`0m|<$
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q,>]f@m
output.writeInt(nStartPos.length); {@X)=.Zf
for(int i=0;i<nStartPos.length;i++) _s0;mvz'
{ S1*xM
// output.writeLong(nPos); @$|bMH*1:
output.writeLong(fileSplitterFetch.nStartPos); [jKhC<t}
output.writeLong(fileSplitterFetch.nEndPos); t "[2^2G
} !ac,qj7spa
output.close(); Vfr.Yoy
} ]RI+:f
catch(IOException e){e.printStackTrace ();} mv`ND&
catch(Exception e){e.printStackTrace ();} /Nd`eUn
} JHsxaX;c
zW; sr.
2Ni {fC?
//读取保存的下载信息（文件指针位置） '!XVz$C
private void read_nPos() oMb@)7
{ kfs[*ku
try{ Uj)`(}r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5oY^;)\/
int nCount = input.readInt(); K!|J/W
nStartPos = new long[nCount]; =D^R,Q
nEndPos = new long[nCount]; J+Zp<Wu-
for(int i=0;i<nStartPos.length;i++) !='L`.
{ AbOF/g)C
nStartPos = input.readLong(); -pm%F8{T]
nEndPos = input.readLong(); >+ku:<Hw%.
} ys}I~MK-
input.close(); EpH\;25u
} zCFXQi
catch(IOException e){e.printStackTrace ();} Jw -3G3h
catch(Exception e){e.printStackTrace ();} sK|+&BC
} "l-R|>6~
OP\m~1
mqoB]H,
private void processErrorCode(int nErrorCode) nW_cjYS%
{ \2y[Hy?
System.err.println("Error Code : " + nErrorCode); LVBE+{P\5?
} )SWLX\b
![aa@nOSa
8/ PS#dM\
//停止文件下载 .]K{8[:hq
public void siteStop() :z%q09.)
{ %1kIaYZ
bStop = true; <2fgao&-n
for(int i=0;i<nStartPos.length;i++) 7NQEnAl
fileSplitterFetch.splitterStop(); a/lTQj]A
%bgUU|CdA
Kr@6m80E5
} =$F<Ac;&
} yey]#M[y
//负责部分文件的抓取 t/(rB}
**FileSplitterFetch.java R2f^dt^
*/ h%>yErs
package NetFox; (cm8x
9wP,Z"
I*l y 7z
import java.io.*; cPPTGpqw
import java.net.*; %HcCe[d5l
}<=_&n
"<yJ<lS&>
public class FileSplitterFetch extends Thread { klx28/]
Q-y`IPtA<
J*+[?FXRL
String sURL; //File URL Zd8`95
long nStartPos; //File Snippet Start Position u\o~'Jz
long nEndPos; //File Snippet End Position {Z^q?~zC[
int nThreadID; //Thread's ID D`2w>{Y
boolean bDownOver = false; //Downing is over fsUZG6
boolean bStop = false; //Stop identical w'a3=_nW
FileAccessI fileAccessI = null; //File Access interface rE9Nt9}
S0!w]Ku
}5lC8{wZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p?'&P!
{ x5eSPF1
this.sURL = sURL; -$cO0RSY
this.nStartPos = nStart; b VcA#7 uA
this.nEndPos = nEnd; ~Nn}FNe
nThreadID = id; O#x=iZI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OzUo}QN
} ;><m[l6
aQglA
P$*9Z@
public void run() WSOz^]
{ /G= ?E]^
while(nStartPos < nEndPos && !bStop) -qdt$jIM
{ 28LYGrB
Pd;Gc@'~
q:u,)6
try{ tYMPqP,1.
URL url = new URL(sURL); 9G^gI}bY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZMO ym=
httpConnection.setRequestProperty("User-Agent","NetFox"); WGHf?G/s
String sProperty = "bytes="+nStartPos+"-"; 40HhMTZ0-
httpConnection.setRequestProperty("RANGE",sProperty); #;/ob-
Utility.log(sProperty); 1EA#c>I$
d VyT`
3U%kf<m=
InputStream input = httpConnection.getInputStream(); R0YWe
//logResponseHead(httpConnection); y'm5Z-@o6
'C) v?!19
*g[MGyF"
byte[] b = new byte[1024]; Cm;M; ?
int nRead; &6nLnMF8x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nfksi``Vq
{ hd@jm^k
nStartPos += fileAccessI.write(b,0,nRead); 2&XNT-Qm
//if(nThreadID == 1) Tb}op XYK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1,4#8tB
} IO<Ds#(
heQyz|o
|G/WS0
Utility.log("Thread " + nThreadID + " is over!"); 2ae"Sd!-2
bDownOver = true; <"{VVyK
//nPos = fileAccessI.write (b,0,nRead); z['2
} ~,.'#=V
catch(Exception e){e.printStackTrace ();} ) (0=w4
} DqHJ *x4
} UHR%0ae
Lr0:yo
Y-lTPR<Eq
//打印回应的头信息 G%viWWTY
public void logResponseHead(HttpURLConnection con) (@V_47o
{ |!{Y:f;
for(int i=1;;i++) `N8t2yF
{ *auT_*
String header=con.getHeaderFieldKey(i); (#8B
if(header!=null) z0@BBXQ`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ox5WboL
Utility.log(header+" : "+con.getHeaderField(header)); Z?u}?-b1\H
else 3%)@c P:?
break; (C0Wty
} UjS+Ddp
} /[E2+g
b>Ea_3T/
OAf}\
public void splitterStop() ~I;|ipK4m
{ |G_,1$
bStop = true; l2ie\4dK@
} k~)@D| ?
*Sps^Wl
h s_x @6
} zI4d|P
2S-f5&o
#_WkV
/* -F_cBu81V
**FileAccess.java `\GRY @cg
*//文件访问(定位，写) \,'4eV
package NetFox; A?ho<@^
import java.io.*; u;+8Jg+xH/
RAWzQE}
I51I(QF=
public class FileAccessI implements Serializable{ 3)I]bui
@saK:z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @WNqD*)1
RandomAccessFile oSavedFile; ~tn$AtK
long nPos; 2MmHO2
f3S 8~!
ubRhJ~XB
public FileAccessI() throws IOException (2UA,
{ }B_?7+
this("",0); 70 Ph^e)
} r6GXmr
Kg`P@
X,bhX/h
public FileAccessI(String sName,long nPos) throws IOException Lp/'-Y_
{ !{fu(E
oSavedFile = new RandomAccessFile(sName,"rw"); c\/-*OYr<
this.nPos = nPos; q"EW*k+ )
oSavedFile.seek(nPos); {Qc,Nl [?
} xojt s;n
F{^\vFp
Y`d@4*FN$
public synchronized int write(byte[] b,int nStart,int nLen) '#SZ|Rr6tX
{ )O5@R
int n = -1; :{4C2qK>
try{ \;KSx3o
oSavedFile.write(b,nStart,nLen); q*94vo-
n = nLen; /:ZwGyT;
} vG7Mk8mIr
catch(IOException e) r+h%a~A#>
{ Xu E' %;:
e.printStackTrace (); g9CedD%40
} C#e :_e]
QUaV;6 4
+~ Hb}0ry
return n; V^4v`}Wgx
} ;u[:J
&n6L;y-
dm]g:KWg
} RN|Bk
u})*6l.
mln4Vl(l2M
/* WrcmC$ff
**SiteInfoBean.java #d*0 )w
*/ RyU8{-q
package NetFox; 5*+DN U@
'J3yJ{
7VG*Wu
public class SiteInfoBean { -agB ]j
_>n)HG
yf!7 Q>_G^
private String sSiteURL; //Site's URL A FBH(ms't
private String sFilePath; //Saved File's Path P3-O)m]jv
private String sFileName; //Saved File's Name o.w/?
private int nSplitter; //Count of Splited Downloading File _|W&tB*
?iV}U
m mZP;
public SiteInfoBean() 'wtb"0 }
{//nSplitter的缺省值为5 {&XTa`C
//default value of nSplitter is 5 tzfyS#E
this("","","",5); B9[vv;lzu
} ~cyKPg6
60]VOQku
|&xaV-b9W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wN10Drc
{ 4`mf^Kf
sSiteURL= sURL; Ph%ylS/T{
sFilePath = sPath; {[`(o 0@(
sFileName = sName; I'^XEl?
this.nSplitter = nSpiltter; !.^x^OK%y
\y%"tJ~N{
9C2pGfEbn}
} EpKZ.lCU
#d3_7rI0V
V=p"1!(
public String getSSiteURL() e$P^},0/
{ TB?'<hD:
return sSiteURL; 0Ze&GK'Hf
} .>}I/+n
R9^vAS4t[O
H\n6t-l
public void setSSiteURL(String value) DTuco9yr[
{ EC0B6!C&7
sSiteURL = value; ;dMr2y`6
} H! 5Ka#B
8+dsTX`|S
JP0aNu
public String getSFilePath() -^yc<%U
{ fZr{x$]N0
return sFilePath; a%BC{XX
} 3UW`Jyd`k
uL-kihV:-
&=*1[j\
public void setSFilePath(String value) =,q/FY:
{ lhJY]tQt/
sFilePath = value; t#_6GL
} _Dqi#0#40p
Lg(G&ljE@k
V`LE 'E
public String getSFileName() j^8HTa0Cy|
{ sC[#R.eq
return sFileName; sk<S`J,M/_
} 88X]Uw(+
=WI3#<vDG
D</?|;J#/
public void setSFileName(String value) R!7--]Wcg
{ .sQV0jF{
sFileName = value; !`7evV:
} T+~&jC:{
H1%o)'Kut4
l{.PyU5)
public int getNSplitter() Lg,ObVt!
{ 0PFC%x
return nSplitter; +PLJ
} #K@!jh)y^
LgX2KU"
8YE4ln
public void setNSplitter(int nCount) 04=RoYMM
{ ^`dMjeF
nSplitter = nCount; *oIIcE4g7
} 0S;Ipg
} t4d/%b~{:U
YGM7?o
0vDvp`ie#4
/* roAHkI
**Utility.java 2B6u) 95
*/ Gs|a$^V|o
package NetFox; % q!i
]e5aHpgR=
@oj_E0i3
public class Utility { F?MVQ!K*
%La/E#
<3tf(?*,k]
public Utility() SJO*g&duQ
{ z=>PjIW
>k@{NP2b
r/0#D+A
} 7^Us
q[vO mes
//线程睡眠 S/y(1.wh
public static void sleep(int nSecond) FMn|cO.vEP
{ d^$cx(2$D
try{ GmJ \3]{PZ
Thread.sleep(nSecond); rVsCJuxI
} i@WO>+iB
catch(Exception e) tRc3<>
{ J32{#\By
e.printStackTrace (); `WC4:8
} bT9:9LP
} S\sy^Kt~4:
y|*4XF<b
//日志 ho~WD'i
public static void log(String sMsg) L{&1w
{ gMq;
System.err.println(sMsg); =? q&/ cru
} I|Hcs.uW
d/*EuJYin<
\!uf*=d
public static void log(int sMsg) )PU\|I0|)e
{ s/E9$*0
System.err.println(sMsg); 6rG7/
} U:MZN[Cc[
} Ue,eEer
23p.g5hJi
5HL>2 e[
/* a04S&ezj
**TestMethod.java jamai8
*/ }l]r-
package NetFox; HP3%CB
E6G;fPd= E
T?u*ey~Tv
public class TestMethod { Y%]g,mG
6~s{HI!
c(?OE' "Z
public TestMethod() ?&1%&?cg9
{ ///xx/weblogic60b2_win.exe rSW{1o'
try{ ji,`?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >2mY%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aOoWB^;6
SiteFileFetch fileFetch = new SiteFileFetch(bean); [czWUD
fileFetch.start(); :t+LuH g
} 5HvYy *B/
catch(Exception e){e.printStackTrace ();} O,J,Q|`H&
ov!L8 9`[u
lu1T+@t
} 5=8_Le
hiR+cPSF
l>HB0o
public static void main(String[] args) =5%}CbUU)4
{ ={190=\9
new TestMethod(); ;lTgihW-
} <_bGV
} b%X}{/n
点击下载更多相关资料