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)); nz{ ;]U1
} |u r/6{Oj1
for(int i=0;i<nEndPos.length-1;i++) KpHt(>NR
{ =NHE_4/p
nEndPos = nStartPos[i+1]; 9Fo00"q
} 4?+K:e #F
nEndPos[nEndPos.length-1] = nFileLength; 75@!j[QL<
} [v@3|@
} 4Zz%vY
cyM9[X4rC
3.i$lp`t
//启动子线程 @uh^)6i]/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %7w=;]ym
for(int i=0;i<nStartPos.length;i++) k#eH Q!
{ $|kq{@<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "_LDs(&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v|!u]!JM
nStartPos,nEndPos,i); {6*$yLWK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :G.u{cw
fileSplitterFetch.start(); ;(&$Iw9X
} :B^YK].
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lN(|EI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hgYi ,e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6o5NeKZ
nEndPos = " + nFileLength); oI\Lepl*
// fileSplitterFetch[nPos.length-1].start(); _GhP{C$
7 XNZEi9o
2XX-
//等待子线程结束 d}RU-uiW
//int count = 0; (Q]Ww_r~
//是否结束while循环 tPp9=e2[s
boolean breakWhile = false; l|kGp~
N8[ &1
VyMFALSe]h
while(!bStop) #QUQC2P(~
{ V=i/cI\
write_nPos(); 1Yk!R9.
Utility.sleep(500); x?"+Or.h
breakWhile = true; n 3eLIA{
+g9CklJ
]>9[}'u
for(int i=0;i<nStartPos.length;i++) 9ZD>_a
{ whW%c8
if(!fileSplitterFetch.bDownOver) +=Y[RCXT
{ 3(oB[9]s
breakWhile = false; h5o6G1ur
break; wbpz,
} N,3 )`Vm
} v:IpZ;^
if(breakWhile) 1 u~Xk?
break; )MWbZAI
Hk 0RT%PK
z%q)}$O
//count++; _'mK=`>u
//if(count>4) ]as+gZ8
// siteStop(); Z~3
} y$K[ArqX
\S_o{0ZY}
t"$#KP<
System.err.println("文件下载结束！"); jmBsPSGIC
} &SW~4{n:
catch(Exception e){e.printStackTrace ();} h( DmSW
} I_s*pT
sTu]C +A
/tG[pg{[
//获得文件长度 e9;5.m
public long getFileSize() K2qKkV@
{ p_B5fm7#6W
int nFileLength = -1; nu `R(2/
try{ ZA7b;{o [
URL url = new URL(siteInfoBean.getSSiteURL()); 3rj7]:Vr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8\S$iGd
httpConnection.setRequestProperty("User-Agent","NetFox"); [{q])P;
AIG5a$}&
V4ybrUWK
int responseCode=httpConnection.getResponseCode(); @M*oq2U;
if(responseCode>=400) -`CE;
{ c=f;3N
processErrorCode(responseCode); ]1s6=
return -2; //-2 represent access is error HE:]zH
} lNo]]a+_
V X.9mt
wz{&0-md*'
String sHeader; x3l~kZ(
owzcc-g
r-AD*h@QZ
for(int i=1;;i++) 'd]t@[#
{ {XH3zMk[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /],9N
//Utility.log(in.readLine()); 1nR\m+{
sHeader=httpConnection.getHeaderFieldKey(i); hz+c]K
if(sHeader!=null) -VvN1G6.x?
{ fuT Bh6w&
if(sHeader.equals("Content-Length")) /<k]mY cu
{ pB0 SCS*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +t8#rT ^B
break; K(AZD&D
} c#Qlr{ES
} xk7VuS*
else i,mZg+;w
break; Pp.]/;
} N_E)f
} ~!P&LZ
catch(IOException e){e.printStackTrace ();} yeLd,M/I
catch(Exception e){e.printStackTrace ();} ),lE8A{ H
#i=m%>zjN
_adW>-wQ!d
Utility.log(nFileLength); UlPhW~F)
X2`n&JE
MaZVGrcC
return nFileLength; NbK67p:
} SP;1XXlL
|?v+8QL,;t
y>c Yw!
//保存下载信息（文件指针位置） ri49r*_1
private void write_nPos() ;pqS|ayl
{ TiKfIv
try{ @xr}(.
output = new DataOutputStream(new FileOutputStream(tmpFile)); L0*f(H
output.writeInt(nStartPos.length); bUe6f,8,
for(int i=0;i<nStartPos.length;i++) 0GQKM~|H
{ Bqw/\Lxwlf
// output.writeLong(nPos); t\O#5mo
output.writeLong(fileSplitterFetch.nStartPos); @%8$k[
output.writeLong(fileSplitterFetch.nEndPos); 2tS,q_-=
} M %!O)r#Pn
output.close(); &X,6v
} j2oU1' b
catch(IOException e){e.printStackTrace ();} !.7m4mKzo
catch(Exception e){e.printStackTrace ();} [j?<&^SW
} >0cg
=WK's8FB;8
u6 4{w,
//读取保存的下载信息（文件指针位置） Zbf~E {
private void read_nPos() db.~^][k
{ ,vB nr_D#
try{ a``Q}.ST
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); of>H&G)@
int nCount = input.readInt(); < Q6
nStartPos = new long[nCount]; Q 822 #
nEndPos = new long[nCount]; LAuaowE\v
for(int i=0;i<nStartPos.length;i++) Wqe0m_7
{ AIw~@*T
nStartPos = input.readLong(); :`S\p[5
nEndPos = input.readLong(); AbB+<0
} ySHio;g9
input.close(); ooj^Z%9P
} [@0Hmd7
catch(IOException e){e.printStackTrace ();} 5KW n>n
catch(Exception e){e.printStackTrace ();} L"}2Y3
} \F<C$cys\
NZ-57Ji
=91f26c!~
private void processErrorCode(int nErrorCode) r|3<UR%
{ x";4)u=
System.err.println("Error Code : " + nErrorCode); 5yf`3vV|3@
} &&Otj-n5
/p)y!5e
O*9d[jw[
//停止文件下载 *7C l1o
public void siteStop() uP1]EA
{ VW:Voc
bStop = true; AZnFOS
for(int i=0;i<nStartPos.length;i++) uy([>8uu
fileSplitterFetch.splitterStop(); j^D/,SW
1t7T\~+F
2'8I/>-
} +[#^c3x2
} "SpsSQ
//负责部分文件的抓取 "gt*k#
**FileSplitterFetch.java lht :%Ts$
*/ WISeP\:^
package NetFox; LF!S`|FF
_:G>bU/^
$ 3R5p
import java.io.*; $~T|v7Y%
import java.net.*; dbfI!4
8CRwHDB
1fV\84m^
public class FileSplitterFetch extends Thread { MwWN;_#EO)
K# h7{RE
'^BTa6W}m
String sURL; //File URL Rc~63![O.
long nStartPos; //File Snippet Start Position 2~@Cj@P]
long nEndPos; //File Snippet End Position !-8y;,P
int nThreadID; //Thread's ID Bacmrf
boolean bDownOver = false; //Downing is over vH{JLN2
boolean bStop = false; //Stop identical @Cl1G
FileAccessI fileAccessI = null; //File Access interface S,#UA%V"
8[u$CTl7a
I_na^sh*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }1YQ?:@
{ 'l._00yu
this.sURL = sURL; _@sSVh$+
this.nStartPos = nStart; 27UnH: =
this.nEndPos = nEnd; %kiPE<<x
nThreadID = id; 6{2 9cX.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \C`2z]V%
} t,qz%J&a
4M>EQF&
`YK#m4gc
public void run() 0|~3\e/QV
{ m"~),QwF9
while(nStartPos < nEndPos && !bStop) BtKbX)R$J
{ tZA%^Y
[?F]S:/i
z5t"o !
try{ - s0QEQ
URL url = new URL(sURL); ;})so
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &MGM9 zm-]
httpConnection.setRequestProperty("User-Agent","NetFox"); g;!,2,De}
String sProperty = "bytes="+nStartPos+"-"; L_fiE3G|>
httpConnection.setRequestProperty("RANGE",sProperty); X1GM\*BE
Utility.log(sProperty); v;IuB
>\>!Q V1@
k E-+#p
InputStream input = httpConnection.getInputStream(); RGLi#:0_.x
//logResponseHead(httpConnection); c4L++ u#
MW)=l | G
oY7 eVuz
byte[] b = new byte[1024]; 2$?j'i!
int nRead; ),f d,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @%[ VegT
{ r~T3Ieb
nStartPos += fileAccessI.write(b,0,nRead); CM+/.y T
//if(nThreadID == 1) ]s~%1bd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xldz&&@
} ;Y`k-R:E6A
%o#|zaK
k_7agW
Utility.log("Thread " + nThreadID + " is over!"); ]o*-|[^?
bDownOver = true; K?acRi
//nPos = fileAccessI.write (b,0,nRead); 9E]7Etfw
} `Qo}4nuRs
catch(Exception e){e.printStackTrace ();} ??=7pFm
} $|}PL[aA#
} ~bLhI
z|i2M8
Q#*Pjl
//打印回应的头信息 zNJ-JIo%
public void logResponseHead(HttpURLConnection con) G>0hi1
{ N1u2=puJY
for(int i=1;;i++) RTvzS]
{ gqan]b_
String header=con.getHeaderFieldKey(i); ^ot9Q
if(header!=null) "SN+ ^`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $nW^Gqwj]1
Utility.log(header+" : "+con.getHeaderField(header)); g+M& _n
else ;U$EM+9
break; [;hCwj#
} [5QbE$
} %%f(R7n
g'1ASMuR
\o{rw0w0
public void splitterStop() =hB0p^a
{ J9yB'yE8
bStop = true; .?p\=C@C+
} /V)4B4
s+XDtO
L\("
} T&~7*j(|e
V-TWC@Y"
"4e{Cq
/* YR}By;Bq
**FileAccess.java 7H5t!yk|9
*//文件访问(定位，写) Gmp`3
package NetFox; JLH,:2
import java.io.*; It3.
&[|P/gj#>
[*AWCV
public class FileAccessI implements Serializable{ ;f)o_:(JJ
iHL`r1I!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B!zqvShF
RandomAccessFile oSavedFile; ,=Fn6'
long nPos; J}J7A5P
hpOUz%
z^=e3~-J
public FileAccessI() throws IOException BbdJR]N/!h
{ ccu13Kr>E
this("",0); h1 (MvEt
} 8QNd t
-S,xR5
]J* y`jn
public FileAccessI(String sName,long nPos) throws IOException wz(D }N5
{ uepL"%.@7|
oSavedFile = new RandomAccessFile(sName,"rw"); a4L0Itrp
this.nPos = nPos; lSk<euCYs
oSavedFile.seek(nPos); 3JR1If
} oK3aW6
t@O4!mFH
f8'$Mn,
public synchronized int write(byte[] b,int nStart,int nLen) }lzN)e
{ 9?_ybO~Oq
int n = -1; bn$}U.m$-
try{ tSvklI
oSavedFile.write(b,nStart,nLen); {k}EWV
n = nLen; f YuM`O
} j2/3NF5&
catch(IOException e) 6(X5n5C
{ MN22#G4j^w
e.printStackTrace (); yw(E}
} GqrOj++>
Iu -CXc
AIXvS*Y,
return n; WZ<kk T
} 0y3<Ho,+$
!tNJLOYf
Fc"&lk4e
} *!gj$GK@%
k9^Vw+$m
#Rkldv'
/* ) -C9W7?I
**SiteInfoBean.java XI*_ti
*/ C;jV{sb9c
package NetFox; .u_k?.8|
%ycCNS
"k${5wk#Fl
public class SiteInfoBean { ;Q]j"1c
IHg)xZ
L#`9# Q
private String sSiteURL; //Site's URL v0dFP0.;&
private String sFilePath; //Saved File's Path f~.w2Cna
private String sFileName; //Saved File's Name /~LXY<-(
private int nSplitter; //Count of Splited Downloading File ecH-JPm'
Z-{!Z;T)z
(&6C,O~n^.
public SiteInfoBean() /I'n]
{//nSplitter的缺省值为5 ?]=fC{Rh
//default value of nSplitter is 5 lK? Z38
this("","","",5); / h6(!-"
} Z`?<Ada
wnE c
$<UX/a\sH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0)8QOTeT
{ ItTIU
sSiteURL= sURL; JL9d&7-
sFilePath = sPath; lbES9o5
sFileName = sName; :`Kr|3bQ
this.nSplitter = nSpiltter; @HfWAFT
RT45@
O8+[)+6^
} 4JHQ^i-aY
Or9@X=C
~EU[?
public String getSSiteURL() 3_atv'I
{ 4Pljyq:
return sSiteURL; <(JsB'TK
} n/"T7Y\2
6Upg\(
wE75HE`gW
public void setSSiteURL(String value) /s%I(iP4
{ 1>*]jj}
sSiteURL = value; J{mP5<8>b
} 4:}`X
QD:0iD?
xLZQ\2q
public String getSFilePath() lxK_+fj q
{ yvxC/Jo4
return sFilePath; 6QRfju'
} k~Pm.@,3o
zJMKgw,i*
l\^q7cXG
public void setSFilePath(String value) );h\0w>3
{ Z"gllpDr$
sFilePath = value; oQDOwM,
} JLAg-j2
#{0DpSzE5
81_3{OrE<
public String getSFileName() D,eJR(5I
{ Snt=Hil`
return sFileName; H/V%DO
} yj$S?B Ee
p _e-u-
U!a"r8u|8q
public void setSFileName(String value) `OQ&u
{ {NK>9phoB
sFileName = value; ;_i0@@J
} Jb-wvNJu
x=B+FIJ
) Q=G&
public int getNSplitter() GxZQ{ \
{ *vhm
return nSplitter; tL+8nTL
} @sKAsn
16N8h]l
_3p:q.
public void setNSplitter(int nCount) l``1^&K
{ @\l> <R9V
nSplitter = nCount; Re1@2a>
} -e(2?Xq9
} |/fbU_d
[/uKo13
|V9%@ Y?
/* ,H[AC}z2X
**Utility.java 0D#!!r ;
*/ &`L5UX
package NetFox; s*CKFEb#
)+t5G>yKK
:=L[kzX
public class Utility { eZHzo
<Awx:lw.
0K3FH&.%
public Utility() ($(1KE
{ 0v7;ZxD
_z4rx
nv$
} ?XOeMI
T%a]3
//线程睡眠 j|G-9E
public static void sleep(int nSecond) oZCi_g 5i
{ S,(@Q~
try{ [!R%yD;
Thread.sleep(nSecond); x>8f#B\Mr
} <Z8] W1)
catch(Exception e) .hJ8K#r
{ c?R.SBr,'
e.printStackTrace (); f,L
} tiE+x|Ju"
} aq5<Ks`r
<dYk|5AdLF
//日志 Y!7P>?)`,X
public static void log(String sMsg) ?3Jh{F_+
{ CQ( @7
System.err.println(sMsg); !F<?he<U
} PRz oLzr
\34|9#*z-
n#&RY%#`
public static void log(int sMsg) 8S02 3
{ a;S^<8
System.err.println(sMsg); w%_BX3GTO
} o7T|w~F~R
} ]czy8n$+
O^xt
.-|O"H$
/* ]Cz16e&=2
**TestMethod.java 3 #wj-
*/ u=l(W(9=
package NetFox; OX`n`+^D
>gSerDH8\
e"CLhaT
public class TestMethod { W^N"y&
I>5@s;
j%}Jl
public TestMethod() 2bJFlxEU
{ ///xx/weblogic60b2_win.exe `@eH4}L*
try{ G'py)C5;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jwq"B$ap
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yn#h$o<
SiteFileFetch fileFetch = new SiteFileFetch(bean); 19.cf3Dh
fileFetch.start(); 0|ps),
} itF+6wv~
catch(Exception e){e.printStackTrace ();} SHk[X ]Uo
@,MdvR+a
'mcJ/9)v
} Xu_<4
i4I0oRp
eC$v0Gtq
public static void main(String[] args) &FrB6y
{ -"e}YN/
new TestMethod(); x3s^u~C)(w
} ^PQV3\N
} %-l:_A
点击下载更多相关资料