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)); 4K 8(H9(
} *U$%mZS]1
for(int i=0;i<nEndPos.length-1;i++) fe8hgTP|
{ FNw]DJ]
nEndPos = nStartPos[i+1]; z|t2;j[
} M%g2UP
nEndPos[nEndPos.length-1] = nFileLength; X3~`~J
} B4 5#-V
} Ug384RzHN
?<S fhjU
QMy1!:Z&!
//启动子线程 [7NO !^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QKhGEW~G
for(int i=0;i<nStartPos.length;i++) /,~g"y.;,
{ h lSav?V_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @(0O9L F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4dm0:, G
nStartPos,nEndPos,i); ~,Yd.?.TI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IfT: 9 &
fileSplitterFetch.start(); /x4L,UJ= P
} p 16+(m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +DO<M1uE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \#IKirf?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c|Z6p{)V
nEndPos = " + nFileLength); MTq/
// fileSplitterFetch[nPos.length-1].start(); d^zuo
l%p,m[
m77!i>V)
//等待子线程结束 G:@1.H`
//int count = 0; m#-&<=
//是否结束while循环 ddbQFAQQQ
boolean breakWhile = false; T%;NW|mH&
z.+%{_pe
jp1e3 Cg
while(!bStop) 6!N2B[9
{ A8o)^T(vJ
write_nPos(); ig .
Utility.sleep(500); Ps<k2
breakWhile = true; 5X9Lh_p
Pa?{}A
fsWIz1K
for(int i=0;i<nStartPos.length;i++) IVa6?f6H_
{ ;]bW
if(!fileSplitterFetch.bDownOver) kB%.i%9\\
{ _g-0"a{-
breakWhile = false; gVy`||z
break; eKo=g|D
} Z3=N= xY]
} 6urU[t1
if(breakWhile) h0HK~S#xBv
break; G}LV"0?
C\OZs%]At
9XhH*tBn7(
//count++; iXWB
//if(count>4) G]{^.5
// siteStop(); ggm'9|
} ruyQ}b:zS
e,Y<$kPV
C\vOxBAB
System.err.println("文件下载结束！"); /{[p?7x>
} rl&.|;5uH;
catch(Exception e){e.printStackTrace ();} zL3zvOhu}
} $DtUTh3)
SLUQFoz}
8R-;cBT
//获得文件长度 pf+VYZ#)
public long getFileSize() rvK%m_r
{ -t>"s'kv
int nFileLength = -1; #0\* 86
try{ <G`1(,g
URL url = new URL(siteInfoBean.getSSiteURL()); ^HtB!Xc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zSu,S4m_;
httpConnection.setRequestProperty("User-Agent","NetFox"); )[r=(6?n
{`T^&bk
H SGz-
int responseCode=httpConnection.getResponseCode(); x8~*+ j
if(responseCode>=400) <`NsX 6t
{ 3 `mtc@*
processErrorCode(responseCode); TIR Is1
return -2; //-2 represent access is error !IB}&m
} 7s!rer>
& 9 c^9<F
=dQ/^C_hj
String sHeader; 9?~6{!m_9
I0=L_&`)
P=\Hi.]%
for(int i=1;;i++) Y(2Z<d
{ 3(vm'r&5n>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yF%e)6
//Utility.log(in.readLine()); KrHKM3<
sHeader=httpConnection.getHeaderFieldKey(i); !c-MC|
if(sHeader!=null) 0vBQzM Q
{ hY!>>
if(sHeader.equals("Content-Length")) t~nW&]E
{ V@TA~'$|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z"QXPIXPk
break; yLK %lP
} &0"*.:J9
} &^uaoB0
else G;ZN>8NB
break; [McqwU/Q
} a"T+CA
} &-JIXVd*R
catch(IOException e){e.printStackTrace ();} -S&9"=v
catch(Exception e){e.printStackTrace ();} a1u4v/Qu9
[z+YXs!N
^tWSu?9
Utility.log(nFileLength); 6d2eWS
*.+F]-
i[{*(Y$L
return nFileLength; >;%QW
} lA;^c)
lN{>.q@V`r
+aPe)U<t
//保存下载信息（文件指针位置） N'$P( bx
private void write_nPos() 5MZv!N
{ UvB\kIH
try{ ]#rV]As
output = new DataOutputStream(new FileOutputStream(tmpFile)); E}a.qM'
output.writeInt(nStartPos.length); B4+c3M\$V
for(int i=0;i<nStartPos.length;i++) pv&iJ7RN
{ _bg Zl
// output.writeLong(nPos); jVN=_Y}\
output.writeLong(fileSplitterFetch.nStartPos); d(R8^v/L
output.writeLong(fileSplitterFetch.nEndPos); -vk/z+-^!
} GK6CnSV8d
output.close(); UX.rzYM&T
} )1R[X!KQ7
catch(IOException e){e.printStackTrace ();} Tyb'p9
catch(Exception e){e.printStackTrace ();} 0Q8iX)
} g}K/ba'
,1lW`Krx
'&K' 0qG
//读取保存的下载信息（文件指针位置） !W0JT#0
private void read_nPos() 7.g,&s%q
{ WX_g
try{ #UI`+2w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;E5XH"L\
int nCount = input.readInt(); =?wDQ:
nStartPos = new long[nCount]; )hoVB
nEndPos = new long[nCount]; h^`@%g9 S
for(int i=0;i<nStartPos.length;i++) MBKF8b'k
{ kApDD[N
nStartPos = input.readLong(); 8oRq3"
nEndPos = input.readLong(); '"rm66
} qD=b+\F
input.close(); DW:\6k
} eoQt87VCU
catch(IOException e){e.printStackTrace ();} |Zp') JiS
catch(Exception e){e.printStackTrace ();} P*PJ
} Sz')1<
'.S02=/
xcQ^y}JN
private void processErrorCode(int nErrorCode) -;qK_x
{ h<PS<
System.err.println("Error Code : " + nErrorCode); sE|8a
} @ptrF pSL
/~fu,2=7
V|HO*HiB3
//停止文件下载 a[sdYZ
public void siteStop() p?P.BU\CR
{ R3)ccom
bStop = true; ,+gtr.
for(int i=0;i<nStartPos.length;i++) vMn$lT@
fileSplitterFetch.splitterStop(); EUH9R8)
]rg-=Y k
\Ov~ t
} <pS#wTsN4%
} bmKvvq
//负责部分文件的抓取 ]_|%!/_
**FileSplitterFetch.java O(.eHZ=
*/ ^U,C])n
package NetFox; rfSEL 57'
9Q\B1Q
WUQa2$.
import java.io.*; 9]tW;?
import java.net.*; QAY:H@Gt:
dI=&gz
Z7e"4wA
public class FileSplitterFetch extends Thread { d+ $:u
$!z.[GL
MD,BGO?C
String sURL; //File URL YX3NZW2i
long nStartPos; //File Snippet Start Position 07ppq?,y
long nEndPos; //File Snippet End Position r(n>N0:0Ls
int nThreadID; //Thread's ID h_\W7xt
boolean bDownOver = false; //Downing is over XZ(<Mo\v
boolean bStop = false; //Stop identical Gs04)KJm<
FileAccessI fileAccessI = null; //File Access interface k<N5*k8M
RcO.1@2
@|'9nPern
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g^i\7'
{ <5ULu(b&$
this.sURL = sURL; "#f5jH
this.nStartPos = nStart; L}g#h+GP[
this.nEndPos = nEnd; !)}z{,Jx
nThreadID = id; .&>3nu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dWhqu68_
} 2G3Hi;q18
wg:\$_Og
@x*,fk
public void run() 6_tl_O7
{ r.=.,R
while(nStartPos < nEndPos && !bStop) I0^oaccM
{ Upg8t'%{op
sY]pszjT
y4&x`|tv
try{ aan(69=jz
URL url = new URL(sURL); 9p4SxMMO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *Rc?rMF!
httpConnection.setRequestProperty("User-Agent","NetFox"); uY3#,
String sProperty = "bytes="+nStartPos+"-"; YelF)Na
httpConnection.setRequestProperty("RANGE",sProperty); Pt6d5EIG
Utility.log(sProperty); <v\x<ul6
N5xI;UV9'
'68#7Hs.
InputStream input = httpConnection.getInputStream(); |H5$VSw
//logResponseHead(httpConnection); '3E25BsL
`)BZk[64
kpQN>XV#
byte[] b = new byte[1024]; a%/x
int nRead; {OS[0LB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'BVI^H4
{ 5T'viG}%
nStartPos += fileAccessI.write(b,0,nRead); b%VZPKA;
//if(nThreadID == 1) ,}Im^~5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C MGDg}
} PevT`\>
WO^]bR
vsYbR3O
Utility.log("Thread " + nThreadID + " is over!"); _m%Ab3iT~
bDownOver = true; 9.6ni1a'
//nPos = fileAccessI.write (b,0,nRead); )2:U]d%pk
} 6/Z_r0^O
catch(Exception e){e.printStackTrace ();} Scmew
} /-=h|A#Kh
} V.ae 5@;
HisH\z/i5)
Enp;-wG:-
//打印回应的头信息 7--E$!9O,
public void logResponseHead(HttpURLConnection con) +.*=Fn22
{ )R"UX:Q>
for(int i=1;;i++) zzT4+wy`
{ &m TYMpA
String header=con.getHeaderFieldKey(i); F9q!Upr_+
if(header!=null) LftGA7uGJ)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zq|NltK
Utility.log(header+" : "+con.getHeaderField(header)); ]l
else SUsdX[byb
break; _0Y?(}
} #aKUD
} @CC 6`D
i> {0h3Y
e :@PI(P!
public void splitterStop() jRW@$ <mG
{ \+C0Rv^^
bStop = true; J d,9<m$
} shVEAT'`
|HwEwL+
7DeBeY
} # `@jVX0
+.xK`_[M
Lu4>C2{
/* $3eoZ1q'U-
**FileAccess.java VpED9l]y
*//文件访问(定位，写) [-R[rF
package NetFox; `SS[[FT$>
import java.io.*; >U]KPL[%
TA~ZN^xI
FY/F}C,o
public class FileAccessI implements Serializable{ GP`sOPr
7(<r4{1?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _k(&<1i
RandomAccessFile oSavedFile; ]?Q<lMG
long nPos; *mW2vJ/B
vxrqUjK7
Mh}vr%0;)
public FileAccessI() throws IOException _93:_L
{ 7~L_>7;
this("",0); -NA2+].
} O5*3 qJp
$A T kCO
[|(=15;
public FileAccessI(String sName,long nPos) throws IOException #E_<}o
{ 0*AXd=)"*
oSavedFile = new RandomAccessFile(sName,"rw"); 9{IDw
this.nPos = nPos; q&LCMnv"P
oSavedFile.seek(nPos); ylQ9Su>o
} CKC5S^Mx
cV4Y= &
^szi[Cj
public synchronized int write(byte[] b,int nStart,int nLen) P5lk3Zg'
{ Iq 0ew
int n = -1; 1*trtb4F
try{ g3(LDqB'.
oSavedFile.write(b,nStart,nLen); ^^*Ia'9
n = nLen; vXG?8Q
} Xu|2@?l9
catch(IOException e) *dsI>4%m
{ XaMsIyhI
e.printStackTrace (); SUjo%3R
} (?"z!dgc
B_XX)y%V
6wZ)GLW[
return n; =RQI5nHdw
} $\PU Y8
\(r$f!`
;{v2s;
} #J
f|~X}R
b|\dHi2FT
/* Mu6DTp~k
**SiteInfoBean.java -]QP#_
*/ er3`ITp:dp
package NetFox; <*oV-A
//%#?JJV
6-+wfrN2
public class SiteInfoBean { D/hq~- g
m!]J{OGG:
QH?sx k2
private String sSiteURL; //Site's URL V~do6[(
private String sFilePath; //Saved File's Path dAy\IfZX=
private String sFileName; //Saved File's Name `oM'H+
private int nSplitter; //Count of Splited Downloading File Rgl cd
XCO8A\
:@-.whj
public SiteInfoBean() <-,y0Y'
{//nSplitter的缺省值为5 q4,/RZhzh
//default value of nSplitter is 5 M4% 3a j
this("","","",5); ImbA2Gcs
} c:<a"$
7OS i2
):y^g:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ab]Q1kD
{ $9: @M.
sSiteURL= sURL; ew]G@66
sFilePath = sPath; @Bn4ZFB@
sFileName = sName; 'pB?
this.nSplitter = nSpiltter; h0I5zQZm
5".bM8o
GK[9IF#_>
} |nGv:= H@
0G2Y_A&e**
i'\-Y]?[
public String getSSiteURL() u7j,Vc'~
{ ]q4(%Q
return sSiteURL; Kf_xKW)^
} LXPO@2QF
iSg0X8J)
?e,:x ]\L
public void setSSiteURL(String value) Wu(^k25
{ eKZS_Qd
sSiteURL = value; ;zV<63tW
} t*H|*L#YR
C ,|9VH
zQ<;3+*
public String getSFilePath() 4jZB%tH
{ 5HE5$S
return sFilePath; ,KU%"{6
} fNfa.0s
dnQ6Ras
6NHP/bj<1V
public void setSFilePath(String value) MUGoW;}v)
{ oe0YxSauL
sFilePath = value; O'{kNr{u
} ,np|KoG|M
B692Mn
po,Ue>n/
public String getSFileName() iHK.hs;
{ n&zEYCSI
return sFileName; WWH<s%C
} `%"x'B`mM
}xi?vAaTl
Gf:dN_e6.
public void setSFileName(String value) 5\w*W6y
{ 78~/1-
sFileName = value; c3o3i
} I,HtW),
SJc~E$5<
!`1m.
public int getNSplitter() O:pg+o&
{ 2oRwDg&7|
return nSplitter; z!18Jh
} 9=}[~V n
`h'=F(v(}
~TeOl|!lE+
public void setNSplitter(int nCount) 'mTY56Yq
{ \ym^~ Q|
nSplitter = nCount; MX7Ix{
} \Q1&w2mw
} q9{)nU
!!)$?R;1
?%Tx% dB
/* MPy><J
**Utility.java `Syfl^9B
*/ 4z26a
package NetFox; a?8)47)
$Bl51VjN
R5(([C1
public class Utility { ,Z _@]D@
3S2Alx!6
#7}M\\$M
public Utility() u%E8&T8,
{ U1pE2o-
p@uHzu7
b4bd^nrqV
} ?Tu=-ppw
N-knhA
//线程睡眠 " zD9R4\X.
public static void sleep(int nSecond) SK^(7Ws~0
{ R8eBIJ/@_
try{ Dq$1 j%4Y
Thread.sleep(nSecond); Y~A I2HS
} Az8ZA~Op=
catch(Exception e) QV:> x#=V
{ SE@TY32T
e.printStackTrace (); OdY9g2y#m
} 3o/f, }_
} R){O]<+
(w5cp!qW9J
//日志 %N&W_.F6
public static void log(String sMsg) i8-Y,&>V
{ ~>lqEa
System.err.println(sMsg); ilHf5$
} l&e$:=;8
i20y\V os?
bHE.EBZ
public static void log(int sMsg) ruB D ^-
{ ]&q<O0^'
System.err.println(sMsg); nXoDI1<[
} CMOyK^(e
} $qdynKK
Yk|.UuXT
hhZ%{lqL
/* X#JUorGp
**TestMethod.java {"{]S12N
*/ ~wv$uL8y
package NetFox; $ B&ZnZ?
~&qv[XS
NW`.7'aWT
public class TestMethod { DwGM+)!
#G F.M,O/h
Uuu2wz3O0
public TestMethod() bo\Ah/.
{ ///xx/weblogic60b2_win.exe w?|qKO
try{ Pvi2j&W84
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y)pop:y t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uyB2
SiteFileFetch fileFetch = new SiteFileFetch(bean); _LC*_LT_
fileFetch.start(); 37a1O>A
} fd>{UyU
catch(Exception e){e.printStackTrace ();} GF%/q:9
\OFmd!Cz
!o_eK\p
} Q*ELMib
i.)n#@M2
iz`>'wpC
public static void main(String[] args) :"!Z9l\@
{ YF-E1`+?<
new TestMethod(); 63Gq5dF
} Um4zI>
} .-tR <{ g
点击下载更多相关资料