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)); /i~^LITH
} EV?47\~
for(int i=0;i<nEndPos.length-1;i++) ZR01<V
{ R6WgA@Z|r
nEndPos = nStartPos[i+1]; h<^:Nn
} U<,Kw6K
nEndPos[nEndPos.length-1] = nFileLength; ,Q /nS$
} $bi_i|?
} D@4&@>
,;=( )-
<@AsCiQF
//启动子线程 !$KhL.4P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Mn }Z9S[
for(int i=0;i<nStartPos.length;i++) ("JV:u.L+
{ uZiY<(X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gt t$O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UA!Gr3
nStartPos,nEndPos,i); j~L1~@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %[\Ft
fileSplitterFetch.start(); !qw=I(
} $qUta<o2@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \gI:`>- x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h@m n GE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :2UC{_
nEndPos = " + nFileLength); b-(UsY:
// fileSplitterFetch[nPos.length-1].start(); :kiO
FskJyB[
>eG&gc@$1$
//等待子线程结束 1-NX>E5
//int count = 0; dj'8x48H2W
//是否结束while循环 nwZr3r
boolean breakWhile = false; ,<P[CUD&&
*A1TDc$
}jY[| >z
while(!bStop) W6xjqNU
{ ]20"la5
write_nPos(); X-N$+[#
Utility.sleep(500); IL6f~!
breakWhile = true; "k1Tsd-
=@jMx^A"
ks#Z~6+3
for(int i=0;i<nStartPos.length;i++) /jn3'q_,
{ &pY G
if(!fileSplitterFetch.bDownOver) u g:G9vjQ
{ i(f;'fb*
breakWhile = false; \Af|$9boHz
break; On.x~t
} xE-c9AH
} `w=H'"Zv
if(breakWhile) dK;\`>8
break; .kKwdqO+zB
~!d)J
L|1zHDxQ
//count++; FqUt uN
//if(count>4) q}F%o0
// siteStop(); #HuA(``[d
} O"^a.`27
&P{p\v2Y
4d._Hd='
System.err.println("文件下载结束！"); 6[|<
} "QFADk1
catch(Exception e){e.printStackTrace ();} AB&wn>q
} |m 5;M$M)
?! _pP|
Ee\-q
//获得文件长度 :0j`yo:w
public long getFileSize() //5_E7Ehu$
{ hCvLwZ?LF
int nFileLength = -1; ryp$|?ckJ
try{ #Xw[i
URL url = new URL(siteInfoBean.getSSiteURL()); .nF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kq.h\[
httpConnection.setRequestProperty("User-Agent","NetFox"); vgW1hWmHJ
l 75{JxZX
O-lh\9{'R
int responseCode=httpConnection.getResponseCode(); 07"Oj9NlA
if(responseCode>=400) W]}V<S$
{ %3+hz$E
processErrorCode(responseCode); a={qA4N
return -2; //-2 represent access is error zcWxyLifl0
} "gikX/Co=
5m7Ax]\
I nK)O';
String sHeader; P5xmLefng
wYMX1=
XhD fI &
for(int i=1;;i++) *n_4Rr
{ 8Gg/M%wq9U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |21hY
//Utility.log(in.readLine()); RowiSW
sHeader=httpConnection.getHeaderFieldKey(i); 2T%f~yQ^
if(sHeader!=null) ^?]H$e
{ ftH%, /,
if(sHeader.equals("Content-Length")) TIhzMW\/K
{ :;WDPRx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Eg29|)qsz
break; 5YH mp7c-z
} wVJFA1
} Ml/p{ *p
else J+NK+,_*M
break; OHnjI>/
} 5_C#_=E
} 5t#]lg[06'
catch(IOException e){e.printStackTrace ();} }<h. chz,
catch(Exception e){e.printStackTrace ();} /P"\+Qp
Ib8{+j
khIa9Nm
Utility.log(nFileLength); &FF. Ddt{
?[B[ F
D=sc41]
return nFileLength; j"u)/A8*
} 6:tr8 X_
v]U;5Uo
de47O
//保存下载信息（文件指针位置） Hf{%N'4
private void write_nPos() ^|{fB,B
{ \` ^Tbn:
try{ T|2%b*/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5t?2B]
output.writeInt(nStartPos.length); sLqvDH?V
for(int i=0;i<nStartPos.length;i++) Rs[]i;
{ Lbp6I0&n
// output.writeLong(nPos); l4reG:uYG
output.writeLong(fileSplitterFetch.nStartPos); xi. KD
output.writeLong(fileSplitterFetch.nEndPos); X3O$Sd(D
} Z2jb>%
output.close(); iPO S
} I8;[DP9
catch(IOException e){e.printStackTrace ();} rg/vxTl
catch(Exception e){e.printStackTrace ();} azc:C
} emPm^M5/K
7O^ S.(
:=eUNH
//读取保存的下载信息（文件指针位置） 8vW`E_n
private void read_nPos() &it/@8yH
{ (+ anTA=
try{ :Rj,'uH+h)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n1(X%%2
int nCount = input.readInt(); &)jZ|Q~
nStartPos = new long[nCount]; K)\gbQ|
nEndPos = new long[nCount]; m9cT}x&j
for(int i=0;i<nStartPos.length;i++) r['C.S6
{ 9G/2^PI
nStartPos = input.readLong(); DJ0T5VE W3
nEndPos = input.readLong(); wu&7#![,
} *v/*_6f*
input.close(); :]QxT8B
} E2kRt'~N
catch(IOException e){e.printStackTrace ();} G@!9)v]9
catch(Exception e){e.printStackTrace ();} hP<qKVy
} Q 9<_:3
>D62l*VC)
r!,V_a4n
private void processErrorCode(int nErrorCode) f.^w/ GJO/
{ @2*6+w_Ae
System.err.println("Error Code : " + nErrorCode); tgA |Vwwk
} Pp hQa!F$
S9oGf
]X|G+[Ujv
//停止文件下载 S`w)b'B!M
public void siteStop() !PIdw~YC
{ S]/+n>
bStop = true; D07u?
for(int i=0;i<nStartPos.length;i++) m kf{_!TK
fileSplitterFetch.splitterStop(); PzDgl6C
Asu"#sd
Lo9?,^S
} P<x
} <U pjAuG8
//负责部分文件的抓取 }h6z&:qA[?
**FileSplitterFetch.java TN`:T.B
*/ yo?Q%w'Nh
package NetFox; xR`2+t&t
jpv,0(
cSk}53
import java.io.*; ", )
import java.net.*; 5VbNWrw
i%8 sy
:XZ pnjj
public class FileSplitterFetch extends Thread { :zRboqe(cc
uK5x[m
oH"N>@Vl
String sURL; //File URL F|Q#KwN
long nStartPos; //File Snippet Start Position ^T,cXpx|
long nEndPos; //File Snippet End Position I0RWdOK8K
int nThreadID; //Thread's ID c$fM6M }
boolean bDownOver = false; //Downing is over P,_E 4y
boolean bStop = false; //Stop identical 1hij4m$b
FileAccessI fileAccessI = null; //File Access interface 5wX>PJS
`,d7_#9'
G)7sXEe
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q/?_djv
{ hGV/P94
this.sURL = sURL; Q#KjX;No
this.nStartPos = nStart; `oBzt|f5
this.nEndPos = nEnd; <=M}[
nThreadID = id; o7zfD94I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6u7wfAf
} qr6jn14.c
*/E{s?
n\Ixv
public void run() S &u94hlC
{ ||aU>Wj4
while(nStartPos < nEndPos && !bStop) >,3 3Jx
{ 9lV'3UG-?
4PQWdPv;
KL4/"$l]
try{ Q@n kT1o
URL url = new URL(sURL); e IA=?k.y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J]B5w{??b
httpConnection.setRequestProperty("User-Agent","NetFox"); `l"~"x^Rr
String sProperty = "bytes="+nStartPos+"-"; {eUfwPAa3
httpConnection.setRequestProperty("RANGE",sProperty); 6<Z9p@6
Utility.log(sProperty); h[T3WE
e AjtWqg
[dMxr9M
InputStream input = httpConnection.getInputStream(); :^a$ve3(Jq
//logResponseHead(httpConnection); ,-)1)R\.
N{g=Pf?I}
n4johV.#
byte[] b = new byte[1024]; +E4_^
int nRead; \.] U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E"=$p$k
{ bAp`lmFI
nStartPos += fileAccessI.write(b,0,nRead); GWKefH
//if(nThreadID == 1) ;rgsPVbVf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 51x,[y+Xe
} tO7{g
#Gx@\BE{
~vmY2h\
Utility.log("Thread " + nThreadID + " is over!"); 4a-wGx#h
bDownOver = true; v0=~PN~E
//nPos = fileAccessI.write (b,0,nRead); / yCV-L2J
} {NR~>=~K-
catch(Exception e){e.printStackTrace ();} ]mSVjF3l
} -eTGRr
} =%LS9e^7D
2dfA}i>k
r DuG["
//打印回应的头信息 k"J?-1L
public void logResponseHead(HttpURLConnection con) zVu}7v()
{ OK=t)6&b
for(int i=1;;i++) GF&"nW9A
{ o/R-1\Dn
String header=con.getHeaderFieldKey(i); Wm61
if(header!=null) s/V[tEC*z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t&_lpffv
Utility.log(header+" : "+con.getHeaderField(header)); ^^#A9AM
else vs~*=d27Pf
break; Vs >1%$If
} i^#RiCeo
} UWI5/R
?W()Do1tR
GfDA5v[
public void splitterStop() k4v[2y`
{ ',f[y:v;
bStop = true; U|=y&a2Rb
} *"@P2F&
I,D=ixK
'PZJ{8=
} Gx m"HC
`|R{^Sk1o
K\G|q}E/1
/* TUG3#PSnm*
**FileAccess.java Mtu8zm
*//文件访问(定位，写) x)*[>d2yd
package NetFox; 0!Yi.'+
import java.io.*; Xma0k3;-
;I>`!|mT
kDsUKO p
public class FileAccessI implements Serializable{ _>s.V`N'
#ed]zI9O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6*$N@>8&
RandomAccessFile oSavedFile; y^ohns5{
long nPos; AWw'pgTQX
Lxl?6wZ
(U)=t$=o
public FileAccessI() throws IOException \2YhI0skW
{ 95}"AIi
this("",0); &A~1Q#4
} n}2}4^
Rzp-Q5@MY
p~t$ll0s
public FileAccessI(String sName,long nPos) throws IOException rie1F,
{ \C#Vh7z"2&
oSavedFile = new RandomAccessFile(sName,"rw"); 4_$f"6
this.nPos = nPos; AWw:N6\
oSavedFile.seek(nPos); &f[[@EF7
} ipsNiFv:
so;aN'{6@
bz1\EkLL
public synchronized int write(byte[] b,int nStart,int nLen) bkb}M)C
{ {+!_; zzZ
int n = -1; 2l9_$evK~
try{ kns[b [!H
oSavedFile.write(b,nStart,nLen); s:%>H|-
n = nLen; NFQ0/iuW
} l1@:&j3h
catch(IOException e) =uHTpHR
{ Xr@0RFdr[
e.printStackTrace (); M:ttzsd
} sviGS&J9h
kY|<1Ht
{2!.3<#
return n; (q)W<GYP
} @ ~PL|Pp_
xMe[/7)4
&4DWLI
} ~U`aH~R
gX[6WB"p
y<)x`&pcD
/* f+rBIE
**SiteInfoBean.java wEdXaOEB5
*/ |KuH2,n0
package NetFox; L;Nm"[`
\hg12],#:@
xk#/J]j
public class SiteInfoBean { kc}e},k
T7[ItLZ
$cjidBi`):
private String sSiteURL; //Site's URL ]2?t$"G8
private String sFilePath; //Saved File's Path +g(QF
private String sFileName; //Saved File's Name 8xLvpgcZ
private int nSplitter; //Count of Splited Downloading File -e30!A
)nQ.6
`w2hJP
public SiteInfoBean() 90;[5c
{//nSplitter的缺省值为5 }.x?$C+\"
//default value of nSplitter is 5 a(F%M
this("","","",5); A%pcPzG;
} {@k5e) Q
ENygD
66v6do7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /mmCqP
{ |[8&5[);
sSiteURL= sURL; IG 6yt
sFilePath = sPath; q45Hmz
sFileName = sName; h60*=+vdJ
this.nSplitter = nSpiltter; 4\3Z$%2^LZ
|*Hw6m
U5odSR$
} PC/Oo~Gx
woQYP,
3s" Rv@
public String getSSiteURL() [*@"[u
{ 4;x{@Ln
return sSiteURL; UE5T%zd/
} o@vo,JU
tv5G']vO\
6Z0@4_Y@B6
public void setSSiteURL(String value) aH*)W'N?
{ $0 eyp]XC\
sSiteURL = value; 3V2"1Ic
} ^As^hY^p
LGV"WE
VD,g
public String getSFilePath() n)gzHch
{ ) m[0,
return sFilePath; -b8Vz}Y
} ckS.j)@.c
-m3O\X
V^[o{'+
public void setSFilePath(String value) ,,OO2EgZ`
{ pri=;I(2A
sFilePath = value; b 'jZ4{+W
} /{6PwlP5
P-.>vi^+
u?i_N0H
public String getSFileName() 8i;EpAwB
{ j@ lHgis
return sFileName; f.4r'^
} 2Gd.B/L6
To.CY^M
"k[-eFz/@M
public void setSFileName(String value) )%I2#Q"Nt-
{ 1^jGSB.%A
sFileName = value; yHsmX2s
} ,3=|a|p
Yj;KKgk
~dg7c{o5
public int getNSplitter() ]c4?-Vq%u
{ Dk[m)]w\
return nSplitter; B&3oo
} wylbs@
..'k+0u^
-^yb[b,
public void setNSplitter(int nCount) (e.?). e
{ &@NTedg!
nSplitter = nCount; aNs~Uad1U
} K Rs e
} 4>x]v!d
hH_&42E6
>$Sc}a3
/* :sDE'o
**Utility.java 2:3-mWE
*/ TrD2:N}dI
package NetFox; Er509zZ,[
D+.< kY.
/P { Zo
public class Utility { CobMagPhr
Xfo3fW)s
uyZ
public Utility() ?tx%KU\3
{ J)tk<&X
O<}3\O )G(
ZFYv|2l
} 0N9`WK
nE;^xMOK!
//线程睡眠 t+y$i@R:
public static void sleep(int nSecond) HGIPz{/5U
{ DO6Tz-%o
try{ !D#wSeJ
Thread.sleep(nSecond); q=Xda0c
} 742sqHx
catch(Exception e) a_}k^zw(
{ RI.6.f1dy
e.printStackTrace (); ;J[ed>v;3
} /q[5-96c
} <j\osw1R
max 5s$@
//日志 3>vSKh1z
public static void log(String sMsg) {P/ sxh:e
{ V;}kgWc1
System.err.println(sMsg); o\<m99Ub
} *WTmS2?'h
*XN|ZGl/
[=/Yo1:v
public static void log(int sMsg) 9NzK1V0X
{ _%M+!Ltz
System.err.println(sMsg); 6WI-ZEVp&
} P}kBqMM
} 5@c/,6l
n@1;5)&k~
#WE"nh9f|z
/* 8d4:8}
**TestMethod.java 4sJM!9eb[
*/ -o: ifF|
package NetFox; ;zq3>A
itotn!Wb`
3jR>
public class TestMethod { JdYmUM|K/c
B8=r^!jEL
n{Ce%gy
public TestMethod() uO]^vP]fT
{ ///xx/weblogic60b2_win.exe 7 k:w3M
try{ 8&K1;l }
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |aWeo.;c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *aem5E`c
SiteFileFetch fileFetch = new SiteFileFetch(bean); skSs|slp
fileFetch.start(); Dqxtc|vo
} Gz09#nFZk
catch(Exception e){e.printStackTrace ();} C6<*'5T
~%gO+qD
SK][UxoHm
} Wb)>APL
/kZ{+4M
+F>9hA
public static void main(String[] args) y"bSn5B[
{ p-CBsm5P
new TestMethod(); A5WchS'
} -9D2aY_>
} c>~q2_}W(
点击下载更多相关资料