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)); P"cc$lB~I
} Ha)eeE$
for(int i=0;i<nEndPos.length-1;i++) &|LZ%W0Fb
{ 1;i[H[hNY
nEndPos = nStartPos[i+1]; jt@k<#h~
} #5-0R7\d7
nEndPos[nEndPos.length-1] = nFileLength; _1VtVfiZ{
} d/k&f5
} CD:@OI
AA:Ch?
]6v6&YV
//启动子线程 s_yY,Z:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WJ9Jj69
for(int i=0;i<nStartPos.length;i++) MS%xOB*6
{ vZ\~+qV,A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N1jj\.nB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f`*Ip?V-
nStartPos,nEndPos,i); g<-x"$(C&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /0>Cy\eN0
fileSplitterFetch.start(); M;ac U~J
} #qi@I;;t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '=EaZ>=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +O`0Mc$%'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MR=>DcR
nEndPos = " + nFileLength); J GnL[9P_
// fileSplitterFetch[nPos.length-1].start(); &Y;z[+(P
c!AGKc
o /AEp)8
//等待子线程结束 D0/ \
//int count = 0; Z#IRNFj
//是否结束while循环 ev7Y^
boolean breakWhile = false; )s4#)E1
'oBT*aL
f7mP4[+dS
while(!bStop) f'Dl*d
{ t5G@M&d4Eo
write_nPos(); yf(VwU, x
Utility.sleep(500); I:Wrwd
breakWhile = true; (0g@Z`r
m{gx\a.5
";AM3
for(int i=0;i<nStartPos.length;i++) WBLfxr
{ ,.6Hh'^65^
if(!fileSplitterFetch.bDownOver) /xj^TyWM
{ 2JwR?<n{
breakWhile = false; (dvCejc^p
break; }A;J-7g6
} ^\Gaf5{
} 3yn>9qt
if(breakWhile) l'n"iQ!G
break; )<-\ F%&b
;0(|06=
ZNNgi@6>
//count++; `O ?61YUQH
//if(count>4) }DjW
// siteStop(); 422d4Zu
} ,E2Tw-%
'+LC.lM
i7v> 9p7
System.err.println("文件下载结束！"); 7KXc9:p+
} eD5.*O
catch(Exception e){e.printStackTrace ();} c,-3+b
} .I_Mmaq;i
$x#0m
i;>Yx#
//获得文件长度 `Nmw
public long getFileSize() Y4q;
{ Li)rs<IX;m
int nFileLength = -1; '|V"!R)
try{ i_8v >F
URL url = new URL(siteInfoBean.getSSiteURL()); f-&4x_5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KfD=3h=
httpConnection.setRequestProperty("User-Agent","NetFox"); C)66^l!x
Y@N-q
p(o"K@I
int responseCode=httpConnection.getResponseCode(); 1{{z[w#
if(responseCode>=400) 5jAiqJq~y:
{ %>u(UmFO
processErrorCode(responseCode); 1'ts>6b
return -2; //-2 represent access is error 30 e>C
} =?hGa;/rb
C.`C T7
Q'D%?Vg'
String sHeader; &-M>@BMy
SbS*z:
r$<-2lW
for(int i=1;;i++) u*LMpTnn
{ 6Q\0v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h$]=z\=
//Utility.log(in.readLine()); i[,9hp
sHeader=httpConnection.getHeaderFieldKey(i); /,#HGu]q'
if(sHeader!=null) mN+ w,
{ }t5-%&gBY0
if(sHeader.equals("Content-Length")) zl8O @g
{ 84(NylZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]34fG3D|
break; 0m8mHJ<&
} "&!7wH ,A
} ,6N|?<26O
else j~DTvWg<Jl
break; DAYR=s
} ol^uM .k%_
} VS.~gHx
catch(IOException e){e.printStackTrace ();} +r8:t5:/I
catch(Exception e){e.printStackTrace ();} PD,s,A
e'"2yA8dh"
7nsn8WN[
Utility.log(nFileLength); l 1C'<+2j!
@-B)a Z
K9z 1'k QH
return nFileLength; 0<ze'FbV]
} GhlbYa
;iB9\p$K)
'BUix!k0<
//保存下载信息（文件指针位置） (3. B\8s
private void write_nPos() w^BF.Nu
{ )-jA4!&
try{ Hsdcv~Xr;l
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vv|%;5(
output.writeInt(nStartPos.length); u4eA++eT
for(int i=0;i<nStartPos.length;i++) U!y GZEU"[
{ ^$>Q6.x?*)
// output.writeLong(nPos); Qk5pRoL_
output.writeLong(fileSplitterFetch.nStartPos); r$Gz
output.writeLong(fileSplitterFetch.nEndPos); m[>pv1o
} :ebu8H9f%
output.close(); p+.xye U(
} i#pBzJ
catch(IOException e){e.printStackTrace ();} EOj.Jrs~
catch(Exception e){e.printStackTrace ();} >IT19(J;A
} R(t1Ei.-?
V7S[rI<<r
;:WM^S
//读取保存的下载信息（文件指针位置） #TUuk
private void read_nPos() S' <X)
{ &mPR[{
try{ GEs5@EH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6&,{"N0T
int nCount = input.readInt(); $wm.,Vb
nStartPos = new long[nCount]; 7;8DKY q
nEndPos = new long[nCount]; |a|##/
for(int i=0;i<nStartPos.length;i++) ~[Fh+t(Y
{ 8V?*Bz-4`
nStartPos = input.readLong(); ~@H9h<T
nEndPos = input.readLong(); #;(Q \
} hy}n&h
input.close(); h 7/wkv\y9
} O>c2*9PM
catch(IOException e){e.printStackTrace ();} oC }
catch(Exception e){e.printStackTrace ();} (~Hwq:=.
} uQmtd
hfL8]d-
Q2LAXTF]y
private void processErrorCode(int nErrorCode) JY0}#FtgV
{ C"cBlru8B
System.err.println("Error Code : " + nErrorCode); gyT3[*eh
} ]vQU(@+I
p5V.O20
8b|m66#|
//停止文件下载 TjWMdoU$J
public void siteStop() yyv<MSU8
{ 5M= S7B3=
bStop = true; 0ZJN<AzbA
for(int i=0;i<nStartPos.length;i++) $.Qu55=z<
fileSplitterFetch.splitterStop(); VD0U]~CWR
q+1SU6x'm
+*=?0\
} M1,1J-h
} 5X}OUn8
//负责部分文件的抓取 +V,Ld&r
**FileSplitterFetch.java IWNIk9T,u
*/ |n~Vpy
package NetFox; &B@qb?UE1
E[8i$
'l41];_
import java.io.*; ^!x}e+ o
import java.net.*; EWp'zbWP
'qlWDt/
12S[m~L%
public class FileSplitterFetch extends Thread { oh%/\Xu
- *_"ZgE
e*/ya8p?
String sURL; //File URL jKhj 7dR
long nStartPos; //File Snippet Start Position [+ N 5
long nEndPos; //File Snippet End Position 5imqZw
int nThreadID; //Thread's ID Ku<_N]9
boolean bDownOver = false; //Downing is over L~} 2&w
boolean bStop = false; //Stop identical -^<`v{}Dn
FileAccessI fileAccessI = null; //File Access interface SX6P>:`
J>S`}p
Nbm=;FHB`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v}^ f8nVR
{ jY8u1z
this.sURL = sURL; K0\Wty0
this.nStartPos = nStart; Dwi[aC+k
this.nEndPos = nEnd; ^`Qh*:T$
nThreadID = id; 'P,F)*kh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !e(ZEV g
} $C?G7Vs
"Qxn}$6-
5jBBk*/\
public void run() ^><B5A>;
{ `@r#o&
while(nStartPos < nEndPos && !bStop) js8GK
{ dL!K''24{
+gsk}>"
> [|SF%
try{ rXR}]|;>
URL url = new URL(sURL); >`'>,n|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gHzjI[WI
httpConnection.setRequestProperty("User-Agent","NetFox"); q;a#?Du o
String sProperty = "bytes="+nStartPos+"-"; BA+:}81&<q
httpConnection.setRequestProperty("RANGE",sProperty); ds9`AiCW>
Utility.log(sProperty); *cn#W]AE
tXIre-. 2}
)iG+pP@.@
InputStream input = httpConnection.getInputStream(); Fttny]
//logResponseHead(httpConnection); xuDn:
mmn1yX:d
wOp# mT
byte[] b = new byte[1024]; YErn50L
int nRead; FE/2.!]&o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +6* .lRA
{ B<Ynx_95
nStartPos += fileAccessI.write(b,0,nRead); 7" wn024
//if(nThreadID == 1) :`ysq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UVD::
} HG%H@uK
[+st?;"GF
f-tV8
Utility.log("Thread " + nThreadID + " is over!"); \'L6m1UZ%
bDownOver = true; aUy=D:\
//nPos = fileAccessI.write (b,0,nRead); ZN ?P4#ZS
} nA]dQ+5sT
catch(Exception e){e.printStackTrace ();} m~Dq0 T
} ;v6e2NacM'
} u0J+Nj9
`<>8tZS9"
;61m
//打印回应的头信息 @$79$:q N
public void logResponseHead(HttpURLConnection con) GSW{h[Op
{ ma }Y\(38
for(int i=1;;i++) FK#>E[[
{ Ac.z6]p
String header=con.getHeaderFieldKey(i); uu>[WFh
if(header!=null) ,9#G/nF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g-%uw[pf
Utility.log(header+" : "+con.getHeaderField(header)); Z3R..vy8
else Z<r&- !z
break; ,7M9f
} d~|qx
} jq["z<V)x
't{=n[
"MXd!
public void splitterStop() 2uWzcy ?F
{ DI}h?Uf ,
bStop = true; :7Vm]xd}do
} >CPkL_@VZ=
ORx,n7-
D2!ww{t
} (p14{
J&a887
)hQNIt3o_
/* 2%W(^Lj
**FileAccess.java ~:)$~g7>b
*//文件访问(定位，写) r 'jVF'w
package NetFox; u'K<-U8H
import java.io.*; &9s6p6eb
T"d]QYJS
_i8$!b2Mr
public class FileAccessI implements Serializable{ +]]wf'w
h'-TZXs0e1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cR5<.$aY
RandomAccessFile oSavedFile; syZ-xE]}
long nPos; "W+4`A(/l
8:&@MZQ&!
W&!Yprr
public FileAccessI() throws IOException 0KDDAkR5R
{ bY>o%LL-
this("",0); 2tr2:PB`
} *q0N$}k
`P z !H
>leOyBEAR
public FileAccessI(String sName,long nPos) throws IOException ;C"J5RA
{ WJ.PPq>]F
oSavedFile = new RandomAccessFile(sName,"rw"); 2hu6
this.nPos = nPos; mtOrb9`m
oSavedFile.seek(nPos); S,8zh/1y
} |M K-~ep
P!O#"(r2]
_?r+SRFn
public synchronized int write(byte[] b,int nStart,int nLen) by06!-P0[
{ Qp=uiXs
int n = -1; []2GN{m
try{ B\=&v8
oSavedFile.write(b,nStart,nLen); FFQF0.@EBi
n = nLen; 'qM3.U
} fzKKK+
catch(IOException e) (~OwO_|3
{ ~*[}O)7#
e.printStackTrace (); & aLR'*]6
} ry< P LRN
eQLa.0
{Y@[hoHtF
return n; *m"mt
} l1:j/[B=
~J2Q0Jv
RTU:J67E
} :qZ^<3+:
PT4`1Oy}/1
p>zE/Pw~
/* 0PfFli`2;
**SiteInfoBean.java dg!sRm1iZ:
*/ <Q0&[q;Z
package NetFox; j;y|Ys)I
Qm-P& g-
TXaXJIp
public class SiteInfoBean { f65Sr"qB3
Qh[t##I/
3edAI&a5
private String sSiteURL; //Site's URL /f[_]LeV]
private String sFilePath; //Saved File's Path lrE0)B5F
private String sFileName; //Saved File's Name 4[ra
private int nSplitter; //Count of Splited Downloading File ^ UzF nW@a
8j$q%g
mOB\ `&h5
public SiteInfoBean() xr/k.Fz
{//nSplitter的缺省值为5 Q.\>+4]1&&
//default value of nSplitter is 5 Jc)1}
this("","","",5); dF,FH-
} B<R-|-#
uM}O8N
E;4a(o]{t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,54<U~Lg:
{ P Cf|^X#B
sSiteURL= sURL; %)D7Dr
sFilePath = sPath; q{hq.KZ
sFileName = sName; +Xp;T`,v
this.nSplitter = nSpiltter; H1[aNwLr
rYJ))@
*LRGfk+h
} yjq )}y,tF
Lk9>7xY
="DgrH
public String getSSiteURL() T_uuFL
{ %&XX*& q
return sSiteURL; IT(c'}
} bwJi[xF
~^S-
o FLrSmY)E
public void setSSiteURL(String value) l.x }I"tf
{ A 5 X+Z
sSiteURL = value; Ic K=E]p
} mz*z1`\7v\
\bOjb\ w$
C=IH#E=
public String getSFilePath() {nefS\#{
{ ~@D%qbN
return sFilePath; 6bNW1]rD
} E/ZJ\@gzD
[,^dM:E/
3kCbD=yF
public void setSFilePath(String value) GZEonCk[&
{ $O'2oeM
sFilePath = value; >U<nEnB$?
} "yTh +=
:dN35Y]a
\bic.0-
public String getSFileName() nZCpT |M5
{ EcoUpiL%2
return sFileName; e@=[+iJc
} S=,1} XZ
rR@n> Xx
"t:.mA<v
public void setSFileName(String value) <IyLLQ+v
{ tR*W-%
sFileName = value; 8(5E<&JP
} W \}}gIEM+
9+I/y,aC
Czr4 -#2
public int getNSplitter() I`W-RWZ
{ )O@^H
return nSplitter; `B\KS*Gya#
} i @9Qb
`A'I/Hf5
qTHg[sME
public void setNSplitter(int nCount) (4ci=*3=
{ hcd>A vC8
nSplitter = nCount; 3Ge<G
} u45h{i-e
} h:jI
e4qk>Cw
xrVZxK:!
/* /P!X4~sTM
**Utility.java "gN*J)!x
*/ J)8pqa
package NetFox; +%}5{lu_e
"aWX:WL&}s
>9tkx/J
public class Utility { |<3Q+EB^
B#GZmv1
)fd-IYi-3
public Utility() J;=aIiN]R
{ H"FflmUO
H]i+o6
*T>#zR{
} NkA6Cp[Q,1
W_BAb+$aF
//线程睡眠 DtF![0w/
public static void sleep(int nSecond) <S8I"8{Mb
{ )1Ma~8Y%r
try{ +wz`_i)!
Thread.sleep(nSecond); KSgQ:_u4}
} 8g# Y
catch(Exception e) cB|Cy{%
{ 7<R6T9g
e.printStackTrace (); e1`)3-f
} F`;TU"pDf
} 9Nag%o{*S>
^C:{z)"h
//日志 UYcyk $da
public static void log(String sMsg) (Y'UvZlM%P
{ Nn,vdu{^2
System.err.println(sMsg); xyS2_Q
} "]SJbuzh
[]=FZ`4
~b>nCP8q
public static void log(int sMsg) <nOuyGIZ
{ AF*ni~
System.err.println(sMsg); c?p0#3%L#
} a8bX"#OR&N
} =0PNHO\gl
iJCY /*C}
9LqMQv"xW
/* kH>vD =q>
**TestMethod.java P;L)1 g
*/ r|\5'ZMx
package NetFox; 7zJrT5
LM"W)S
0,1L e$)6
public class TestMethod { PEX26==
k\mXo-:V6
#|{BGVp
public TestMethod() !~lVv&YO
{ ///xx/weblogic60b2_win.exe d5w_[=9U
try{ G_2gKkIK-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;I!+lx3[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :c~9>GCE&
SiteFileFetch fileFetch = new SiteFileFetch(bean); SQdzEF
fileFetch.start(); 4DQ07w
} ;S=62_Un
catch(Exception e){e.printStackTrace ();} =1{H Sf
vWqyZ-p,q
vCy.CN$
} dl*_ m3T
Hl^aUp.c
vpeq:h
public static void main(String[] args) ?VMi!-POE
{ mC*W2#1pF
new TestMethod(); wq:b j=j
} L?3VyBE
} ^w;o\G
点击下载更多相关资料