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)); r.zJ/Tk
} OAz-w
for(int i=0;i<nEndPos.length-1;i++) h%@#jvh?4
{ T?FR@. Rm
nEndPos = nStartPos[i+1]; n?A;'\cK
} 6@ )bZ|
nEndPos[nEndPos.length-1] = nFileLength; R0mWVgoz
} sFxciCpN
} "'"dcA
#/`V.jXt>
P(Hh%9'(
//启动子线程 ZCVN+::Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :YZMRJL
for(int i=0;i<nStartPos.length;i++) l,3[hx
{ 5bKn6O)K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ss7XjWP.}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *,DBRJ_*7
nStartPos,nEndPos,i); !b+Kasss9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D<cHa |
fileSplitterFetch.start(); V]9?9-r
} 3bPvL/\Lb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'H,l\i@"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K<+h/Ok
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nS1D&;#Y
nEndPos = " + nFileLength); {%b-~& F9
// fileSplitterFetch[nPos.length-1].start(); NASRr
)Hy|K1
pc%_:>
//等待子线程结束 ?5 d3k%
//int count = 0; 5ERycC y
//是否结束while循环 C zvi':
boolean breakWhile = false; WChJ <[]W
D*j\gI
`p%&c%*A
while(!bStop) $Mp#tH28
{ 4m6E~_:F
write_nPos(); F 'U Gp
Utility.sleep(500); g< {jgF
breakWhile = true; bXiT}5mJU
j7 D\O
zW^@\kB0D
for(int i=0;i<nStartPos.length;i++) NUH#
{ /P0%4aWu=
if(!fileSplitterFetch.bDownOver) H;$OCDRC
{ aNCIh@m~
breakWhile = false; Ol24A^
break; ,#r>#fi0
} ""ICdZ_A
} PZ"=t!
if(breakWhile) _`zj^*%
break; 6F3#Rxh
7=8e|$K_
ZWSYh>"
//count++; I%whM~M1+
//if(count>4) 3say&|kJ
// siteStop(); LdAfY0
} "tbKKh66
BUcze\+
e;<=aa)}?
System.err.println("文件下载结束！"); !285=cxz
} wvA@\-.+
catch(Exception e){e.printStackTrace ();} kGMI ?
} 7PZ0
rr#&0`]
pVt8z|p_;{
//获得文件长度 &la;Vu"dp
public long getFileSize() fG5U' Vw
{ m$:o+IH/
int nFileLength = -1; b{t'Doe
try{ Uok?FEN
URL url = new URL(siteInfoBean.getSSiteURL()); lM5Xw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =?3D:k7z
httpConnection.setRequestProperty("User-Agent","NetFox"); t3b%f`D
N$H0o+9-Y
,xrXby|R"
int responseCode=httpConnection.getResponseCode(); P-VK=Y1q
if(responseCode>=400) 969*mcq'
{ _*+ 7*vAL
processErrorCode(responseCode); PK5xnT:
return -2; //-2 represent access is error w7]@QTC
} Z!m0nx
[=-?n6
~fE@]~f>
String sHeader; _d&FB~=
wg*2mo
},'2j
for(int i=1;;i++) hof:+aW
{ ajW[}/)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _.OajE\T
//Utility.log(in.readLine()); ^'~+w3M@
sHeader=httpConnection.getHeaderFieldKey(i); [|\~-6"7N|
if(sHeader!=null) RJ1Q.o
{ !~cTe!T
if(sHeader.equals("Content-Length")) C9U~lcIS
{ *S_eYKSl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dg4?,{c9W
break; rm NqS+t
} pUWj,&t
} Zycu3%JI
else z)r)w?A
break; bH&Cbme90-
} w3c[t~R8
} DJ;G0*
catch(IOException e){e.printStackTrace ();} INsc!xOQ
catch(Exception e){e.printStackTrace ();} e;56}w
h84}lxT^]
^PfFW
Utility.log(nFileLength); [Zk|s9
_gjsAbM
e7ixi^Q
return nFileLength; G@anY=D\EB
} CEE`nn
;Id%{1
6)kF!/J
//保存下载信息（文件指针位置） 1_THBL26d
private void write_nPos() %<JjftNQ
{ P7(+{d{
try{ JGp~A#H&
output = new DataOutputStream(new FileOutputStream(tmpFile)); &+=A;Y)
output.writeInt(nStartPos.length); EUU9JnQhBJ
for(int i=0;i<nStartPos.length;i++) C+$dm)M/q
{ PBb@J'b
// output.writeLong(nPos); >n)N=Zyu
output.writeLong(fileSplitterFetch.nStartPos); V4}9f5FR
output.writeLong(fileSplitterFetch.nEndPos); RX%*:lXi_
} !MNUp(:
output.close(); w%)=`'s_
} nM1U=Du
catch(IOException e){e.printStackTrace ();} BDyOX6
catch(Exception e){e.printStackTrace ();} E% Ce/n
} nk]jIRy^T
Z+@"
r>sk@[4h
//读取保存的下载信息（文件指针位置） ]QM6d(zDA
private void read_nPos() )Fk%,H-1
{ =9GL;z:R+
try{ 0Np}O=>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .G#S*L
int nCount = input.readInt(); iV[g.sP-
nStartPos = new long[nCount]; s(J,TS#I]
nEndPos = new long[nCount]; B0NKav
for(int i=0;i<nStartPos.length;i++) ^wCjMi(sj
{ PmO utYV
nStartPos = input.readLong(); MRiQaUg2
nEndPos = input.readLong(); mF[w-<:.d
} ScYw3i
input.close(); f@+[-yF
} as- Z)h[B
catch(IOException e){e.printStackTrace ();} &!vJ3:
catch(Exception e){e.printStackTrace ();} :bFmw dX
} abUvU26t
)V%xbDdS
(Sr&Y1D
private void processErrorCode(int nErrorCode) pj G6v(zK
{ z_~f/
System.err.println("Error Code : " + nErrorCode); UMuqdLaT9
} 8P0XY S@
7OYNH0EH
:O)\v!Z
//停止文件下载 C2Fklp6
public void siteStop() Z!60n{T79c
{ V|ax(tHv
bStop = true; 2cr~/,YY
for(int i=0;i<nStartPos.length;i++) ^[Cpu_]D
fileSplitterFetch.splitterStop(); R_:47.qq
a33}CVG-e3
',?v7&
} kXA o+l
} tzJdUZJ
//负责部分文件的抓取 \,i9m9;y
**FileSplitterFetch.java aG}ju;
*/ : I28Zi*
package NetFox; m+||t
>xws
gEbe6!; q3
import java.io.*; a H'iW)
import java.net.*; QpwOrxI}
t/LQ|/xo
,J"6(nk
public class FileSplitterFetch extends Thread { N_lQz(nG/2
j1%o+#df
d76k1-m\o
String sURL; //File URL l9"0Wu@_x
long nStartPos; //File Snippet Start Position 3~}G~ t
long nEndPos; //File Snippet End Position pw" !iG}
int nThreadID; //Thread's ID hC?:XVt
boolean bDownOver = false; //Downing is over $As;Tvw.
boolean bStop = false; //Stop identical @|v4B[/
FileAccessI fileAccessI = null; //File Access interface <61T)7
AHc:6v^
eTemRNz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n~l9`4wJY
{ q%%8oaEI
this.sURL = sURL; NypM+y
this.nStartPos = nStart; @&t';"AE
this.nEndPos = nEnd; hJ\IE?+
nThreadID = id; ]/hF!eO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VliX'.-
} 0B#9CxU%
R)MWO5
%^f!= *
public void run() xDv$z.=Y
{ i"Hec9Ri
while(nStartPos < nEndPos && !bStop) Md(AqaA
{ c""*Ng*T
N7:=%Fy(
t+7h(?8L
try{ @^]wT_r
URL url = new URL(sURL); 9J h"1i>x2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jh0``{
httpConnection.setRequestProperty("User-Agent","NetFox"); l{ja2brX
String sProperty = "bytes="+nStartPos+"-"; JpqZVu"7
httpConnection.setRequestProperty("RANGE",sProperty); 8\HL8^6c5
Utility.log(sProperty); <0T5W#H`D
4$.$j=Ct."
GTL gj'B
InputStream input = httpConnection.getInputStream(); "<uaG?:
//logResponseHead(httpConnection); iq2)oC_
'8\7(0$c
V/5.37FSb
byte[] b = new byte[1024]; 6t/nM
int nRead; P1KXvc}JGe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X-2rC
{ a,g3/
nStartPos += fileAccessI.write(b,0,nRead); s\i:;`l:=5
//if(nThreadID == 1) |&OW_*l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r8>(ayJ,
} Xmr|k:z
uvR9BL2=
A2>rS
Utility.log("Thread " + nThreadID + " is over!"); XCr\Y`,Z@
bDownOver = true; "~-H]9
//nPos = fileAccessI.write (b,0,nRead); z-};.!L^
} 6Y?%G>$6
catch(Exception e){e.printStackTrace ();} ]Hr:|2|.
} gq9IJ
} vM )2F
p|fSPSz
X,-QxV=lc)
//打印回应的头信息 YuufgPE*H
public void logResponseHead(HttpURLConnection con) i4;`dCT|A
{ rP$vZ^/c
for(int i=1;;i++) o zg%-
{ ZslH2#
String header=con.getHeaderFieldKey(i); k\->uSU9
if(header!=null) {6H%4n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GP=i6I6C
Utility.log(header+" : "+con.getHeaderField(header)); |m{Q_zAB
else !Rp
break; W=b<"z]RE
} %B9iby8)1
} #m>Rt~(,S
:lf;CT6$
OSP#FjH
public void splitterStop() bz5",8Mn
{ /tIR}qK
bStop = true; nADt8
} ~q0g7?}&
'2)c;/-E
DXX(qk)6
} xW|^2k
7C~qAI6Eg
fDe4 [QQ8
/* 55lL aus
**FileAccess.java p}p1>-j
*//文件访问(定位，写) Qa*?iD
package NetFox; _D{zB1d\0
import java.io.*; 'zYKG5A
?}f+PP,
]LGp3)T-
public class FileAccessI implements Serializable{ lIR0jgP@z
Hgu:*iYA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H<tk/\C
RandomAccessFile oSavedFile; <eWGvIEP[
long nPos; g7*"*%v 2
F\pw0^K;N
>R|*FYam
public FileAccessI() throws IOException /JP]5M)
{ f1eY2UtWQ
this("",0); gkxEy5c[
} r]!<iw
7\.Ax
PT2b^PP
public FileAccessI(String sName,long nPos) throws IOException "= H.$ +
{ >&uG1q0p.
oSavedFile = new RandomAccessFile(sName,"rw"); RX]x3-
this.nPos = nPos; G`!ff
oSavedFile.seek(nPos); _W@SCV)yH
} 7lP3\7wD@9
<9za!.(zu
OBF3)L]
public synchronized int write(byte[] b,int nStart,int nLen) }h+_kRQ
{ `b(y 5Z
int n = -1; b0\'JZ
try{ w1zI"G~4/Q
oSavedFile.write(b,nStart,nLen); s3G\L<~mB
n = nLen; qF9rY)ifm
} c[=%v]j:u
catch(IOException e) m7:E73:
{ to0tH^pD
e.printStackTrace (); vBUl6EmWu
} 4SG22$7W
;bt@wgY
~;ink
return n; nMU#g])y)
} ]Ll<
S}"?#=Q.%O
Q:LyD!at
} ^q"wd?((h
&77]h%B>
{Y5h*BD>
/* FNZB M
**SiteInfoBean.java =N,KVMxw
*/ `92 D]^g
package NetFox; `R@24 )
V:42\b7x
b("JgE`
public class SiteInfoBean { PN:8H>
nf< <]iHf
#( nheL
private String sSiteURL; //Site's URL da@y*TO#i
private String sFilePath; //Saved File's Path ;{|a~e?Y
private String sFileName; //Saved File's Name Vvx(7p-GQ
private int nSplitter; //Count of Splited Downloading File 7YbI|~
\h^bOxh
,8uu,,c
public SiteInfoBean() S&-sl
{//nSplitter的缺省值为5 C!w@Naj
//default value of nSplitter is 5 81a&99k#
this("","","",5); /2u;w!oi.
} #f|-l$a)3a
Rn{q/h
ZP)=2'RY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e:[Kp6J
{ ZNB*Azi
sSiteURL= sURL; 9BANCW"
sFilePath = sPath; #py7emu
sFileName = sName; p!'wOThO`
this.nSplitter = nSpiltter; G%YD2<V
f.jAJ; N>
af{;4Cr
} va8:QHdU
1,PFz
v )7d
public String getSSiteURL() 3|:uIoR{
{ v,>F0ofJ
return sSiteURL; %o4d43uZ
} 2|}p&~G(
mKpUEJ<a
SATZ!
public void setSSiteURL(String value) |[34<tIN
{ rvE!Q=y~
sSiteURL = value; x6DH0*[.
} {OAy@6 +
f| N(~
mA^>Y_:
public String getSFilePath() iI&SI#; _
{ =As'vt 0
return sFilePath; *C\4%l
} 7 oZ-D~3
}Pb!u9_
cjN4U [
public void setSFilePath(String value) D'nV &m
{ &I(|aZx?J
sFilePath = value; )%j)*Ymz;
} 6l_8Q w*5I
l3g6y9;
30H:x@='9
public String getSFileName() dN*<dz+4r
{ +}+hTY$a
return sFileName; WZ&#O#(eO`
} r LfS9H
}Xc|Z.6
"\_}"0H
public void setSFileName(String value) M.OWw#?p:_
{ 5h{Hf]A
sFileName = value; LnJ7i"Q
} It_yh #s
t*}<v@,
8=nm`7(]
public int getNSplitter() }p- %~Y
{ JAiV7v4&R
return nSplitter; :m$%D]WY
} ^d=Z/d[
{Zseu$c
_^'k_a
public void setNSplitter(int nCount) ;%k%AXw
{ t#pY2!/T3
nSplitter = nCount; Gc 8
} zIAMM
} 15eHddd
l%w7N9
z:fhq:R(
/* @pS[_!EqYz
**Utility.java d?{2A84S
*/ '\_)\`a|
package NetFox; fglZjT
',&MYm\
[&`>&u@MK
public class Utility { AMm O+E?
^X;>?_Bk
eD(a +El}
public Utility() /6.b>|zF
{ #xo&#FIH
(@#Lk"B
+es6c')
} %4-pw|':
`fV$'u
//线程睡眠 P<(mH=K
public static void sleep(int nSecond) iLI]aZ
{ {r}}X@|5
try{ >WEg8'#O
Thread.sleep(nSecond); iGlZFA
} :OZhEBL&b
catch(Exception e) UCWU|r<s,
{ enrmjA&3
e.printStackTrace (); A3$b_i@P
} sI'HS+~pU
} _ o(h]G1].
W P&zF$
//日志 24Tw1'mW
public static void log(String sMsg) UmuFzw^
{ +~v(*s C
System.err.println(sMsg); gc:>HX);)
} M*HG4(n0
&ivIv[LV
igL^k`&5^"
public static void log(int sMsg) R{B~Now3
{ `qgJE_GC
System.err.println(sMsg); l{AT)1;^
} <>oW f
} `ouzeu9}
:F\f}G3
~e8n yB
/* Ye6O!,R
**TestMethod.java u5ygbCm
*/ (Vv]:Y]
package NetFox; 19t*THgq
yB1>83!q
u\wd<<I']
public class TestMethod { p'4P2
:<gk~3\
FM)*>ax{
public TestMethod() ~] 2R+
{ ///xx/weblogic60b2_win.exe hzb|:
try{ 1aG}-:$t'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J;`~ !g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NZ5~\k
SiteFileFetch fileFetch = new SiteFileFetch(bean); A'8K^,<
fileFetch.start(); Y ckbc6F
} pH[lj8S
catch(Exception e){e.printStackTrace ();} ;gnr\C*G
:bDA<B6bb
;I'/.gW;{
} M(uB ;Te
I>#ChV)(#
u'1=W5$rK
public static void main(String[] args) T7~v40jn|
{ 9A(K_d-!H
new TestMethod(); dCTpO
} Q%2Lyt"(
} CF"3<*%x
点击下载更多相关资料