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)); [N1[khY`
} UQCond+K
for(int i=0;i<nEndPos.length-1;i++) *AA78G|
{ fDZnC Fa
nEndPos = nStartPos[i+1]; fh@/fd
} u&$1XZ!es
nEndPos[nEndPos.length-1] = nFileLength; B \>W
} ^j]"5@f
} `-<m#HF:)d
Bt"*a=t;
30L/-+r1
//启动子线程 |sV@j_TX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; juBzpQYj
for(int i=0;i<nStartPos.length;i++) vz'<i. Yv4
{ L'}^Av_+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mW @Z1Plxs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rcG-Vf@
nStartPos,nEndPos,i); vmT6^G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e}q!m(K]e-
fileSplitterFetch.start(); Zz56=ZX*_
} 0p!N'7N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `;#I_R_K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kl9<l*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1Yy*G-7}
nEndPos = " + nFileLength); dF0:'y
// fileSplitterFetch[nPos.length-1].start(); Kw,ln<)2
}#9 |au`
`pYL/[5
//等待子线程结束 3Tr}t.mt
//int count = 0; ,:"c"
//是否结束while循环 KPs @v@5M
boolean breakWhile = false; )\,hc$<=m
d,%@*v]S
KS(Ms*k;'
while(!bStop) O<6!?1|KP
{ v@ OM
write_nPos(); X>VxE/
Utility.sleep(500); (1?k_!)T
breakWhile = true; ?[S{kMb2
s h^&3}
-xc'P,`
for(int i=0;i<nStartPos.length;i++) "Yf?33UNZ
{ nv"D
if(!fileSplitterFetch.bDownOver) ?c#v'c^=h
{ 4p_@f^v~QH
breakWhile = false; HH,G3~EBF
break; p4I6oS`/.
} ~CL^%\K
} ;gv9J[R
if(breakWhile) t&Z:G<;
break; qf6}\0
SZ"^>}zl=
Gzu $
//count++; KoO\<_@";
//if(count>4) 3?oj46gP
// siteStop(); XW9 [VUW~
} y5bELWA
RBM4_L
Bc2PF;n
System.err.println("文件下载结束！"); *`.4M)Ym~
} LjA>H>8%[
catch(Exception e){e.printStackTrace ();} h;sdm/
} 7q,M2v;
~`x<;Ts
t=oTU,<
//获得文件长度 gEQevy`T%c
public long getFileSize() Cn(0ID+3f
{ @ 6{U*vs
int nFileLength = -1; 80qe5WC.2u
try{ kVb8$Sp
URL url = new URL(siteInfoBean.getSSiteURL()); 4>xv7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WgQ6EV`
httpConnection.setRequestProperty("User-Agent","NetFox"); -QUvd1S40
UHW;e}O5
eA(c{
int responseCode=httpConnection.getResponseCode(); J#'+&DH
if(responseCode>=400) 4`+hX'
{ Oy/+uw^
processErrorCode(responseCode); {,rVA(I@
return -2; //-2 represent access is error Nm]\0m0p-
} fr<, LC.
9K F`9Y
$di8#O*
String sHeader; S\O6B1<:
O<v9i4*
SRx `m,535
for(int i=1;;i++) *S@0o6v
{ mf)o1O&B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (j;6}@
//Utility.log(in.readLine()); "|l-NUe
sHeader=httpConnection.getHeaderFieldKey(i); ,:QDl
if(sHeader!=null) BnLWC
{ N2^B
if(sHeader.equals("Content-Length")) saaN$tU7
{ 0jN?5j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kq0!.455
break; c0%%X!!$
} W!BIz&SY:-
} JH0L^p
else W}U-u{Z
break; 9 6'{ES9D
} V+kU^mI
} /n SmGAO
catch(IOException e){e.printStackTrace ();} :9`T.V<?
catch(Exception e){e.printStackTrace ();} *!*J5/b
cSSrMYX2
Z{ A)
Utility.log(nFileLength); *OQr:e<}
G:2m)0bW
;9hi2_luV
return nFileLength; -v(.]`Wo&;
} &<E*W*b[
w&7-:."1i
8f<[Bu ze
//保存下载信息（文件指针位置） uE6;;Ir#mF
private void write_nPos() Gq/f|43}@O
{ @ 0RB.-
try{ zU9G:jH
output = new DataOutputStream(new FileOutputStream(tmpFile)); kG7q4jFwP
output.writeInt(nStartPos.length); Z)zWfv}
for(int i=0;i<nStartPos.length;i++) ~agzp`!M
{ ^{T3lQvt
// output.writeLong(nPos); )c#m<_^
output.writeLong(fileSplitterFetch.nStartPos); ]jz%])SzH
output.writeLong(fileSplitterFetch.nEndPos); Ppzd.=E
} +89s+4Jn
output.close(); bt,^-gt@
} &ns !\!
catch(IOException e){e.printStackTrace ();} 89@e &h*
catch(Exception e){e.printStackTrace ();} {g>k-.
} })R8VJ&C/
YolO-5
-m:i~^ u
//读取保存的下载信息（文件指针位置） d4#Q<!r
private void read_nPos() I9`R LSn
{ Oop;Y^gG}
try{ KGclo-,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Uk02VuS
int nCount = input.readInt(); jy] hP?QG
nStartPos = new long[nCount]; Dm j^aFB0|
nEndPos = new long[nCount]; F-)lRGw
for(int i=0;i<nStartPos.length;i++) <}3c%Q1
{ %7PprN0>
nStartPos = input.readLong(); 6.Nu[-?
nEndPos = input.readLong(); >a;^=5E
} h7-!q@
input.close(); .oq!Ys4KA
} bqXCe\#
catch(IOException e){e.printStackTrace ();} AFWcTz6#d
catch(Exception e){e.printStackTrace ();} Hb3+$vJ^
} Q)c$^YsI
e'oM%G[
:4"SJ
private void processErrorCode(int nErrorCode) +b.qzgH>r
{ VJX{2$L
System.err.println("Error Code : " + nErrorCode); XB)e;R
} gOI#$-L
`MgR/@%hr
`CI9~h@k
//停止文件下载 \guZc}V]:\
public void siteStop() .[hQ#3)W
{ %:n1S]Vr
bStop = true; mN^92@eebC
for(int i=0;i<nStartPos.length;i++) {6v|d{V+e
fileSplitterFetch.splitterStop(); /vl]Oa&U
!<!sB)
kSH3)CC P
} b'^OW
} xQ62V11R6
//负责部分文件的抓取 8{HeHU
**FileSplitterFetch.java /LM*nN$%
*/ "3{xa;c
package NetFox; ~pn9x;N%H
6y,M+{
:z%vNKy1
import java.io.*; &+-ZXN
import java.net.*; S<f&?\wK=v
w~EXO;L2
J'4{+Q_pa
public class FileSplitterFetch extends Thread { }(AUe5aw`G
>wjWX{&?
aTs5^Kh')
String sURL; //File URL f- pt8
long nStartPos; //File Snippet Start Position V#1_jxP)Q
long nEndPos; //File Snippet End Position X-! yi
int nThreadID; //Thread's ID ~1pJQ)!zlq
boolean bDownOver = false; //Downing is over @5H1Ni5/o@
boolean bStop = false; //Stop identical o$m64l
FileAccessI fileAccessI = null; //File Access interface br}.s@~
36JVnW;
BbZ-dXC<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D>,]EE-
{ ^>uzMR!q5
this.sURL = sURL; sJX/YGHt
this.nStartPos = nStart; h:(Jes2
this.nEndPos = nEnd; -gh',)R
nThreadID = id; l!\C"f1o,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %*<k5#Yq
} <pGPuw|~I
g# :|Mjgh
{a9Z<P
public void run() ??{(.`}R~
{ -8qLshQ
while(nStartPos < nEndPos && !bStop) 9Ps:]Kp!vN
{ ]DdD FLM
MC/$:PV
sMli!u
try{ #$%9XD3
URL url = new URL(sURL); .9> er
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YL&$cT]1
httpConnection.setRequestProperty("User-Agent","NetFox"); it\{#rb=4
String sProperty = "bytes="+nStartPos+"-"; a=k+:=%y
httpConnection.setRequestProperty("RANGE",sProperty); XZuJ<]}X,
Utility.log(sProperty); a=gTGG"9
&Z5$ 5,[
0G9@A8LU
InputStream input = httpConnection.getInputStream(); Giz9jzF\
//logResponseHead(httpConnection); *#Hi W)
]c+qD,wqt>
<"/Y`/
byte[] b = new byte[1024]; E8=.TM]L
int nRead; %p"x|e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '/SMqmi
{ SxC$EQgL
nStartPos += fileAccessI.write(b,0,nRead); $I-$X?
//if(nThreadID == 1) ExI?UGT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3j0/&ON
} JGf6*D"O
8nQlmWpJ
a9"x_IVU
Utility.log("Thread " + nThreadID + " is over!"); OnF+
bDownOver = true; @\Sa)
//nPos = fileAccessI.write (b,0,nRead); J$&!Y[0
} ]1%H.pF
catch(Exception e){e.printStackTrace ();} }f^r@3Cb3
} eGvHU ;@
} 9#/z[!
<!K2xb-d^
u~Q0V J~
//打印回应的头信息 J'Yj_
public void logResponseHead(HttpURLConnection con) tQ'E"u1
{ G=!Y~qg
for(int i=1;;i++) q NU\XO`H
{ wsP3hE' ]
String header=con.getHeaderFieldKey(i); 5bv(J T
if(header!=null) XYWGX;.=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V>@NkQ<|y
Utility.log(header+" : "+con.getHeaderField(header)); aCX](sN
else {{f%w$r(
break; LcE!e%3
} }@4m@_gR?
} }0?642 =-
+KDB^{
I5Foh|)
public void splitterStop() h(]O;a-
{ i5|A\Wv"
bStop = true; J^pL_
} >AV-i$4eQ@
xv's52x
s}`ydwSg8
} w@nN3U+
;_of'
waQNX7Xdn
/* c_O|?1
**FileAccess.java QgEG%YqB
*//文件访问(定位，写) bL!NT}y`
package NetFox; f'aUo|^?
import java.io.*; "2 ma]Ps
,L\OhT
%D\TLY
public class FileAccessI implements Serializable{ /Y:_qsO1
B y6:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9HRYk13ae
RandomAccessFile oSavedFile; WY?(C@>s
long nPos; p{t2pfb
Sq UoXNw
'_g8fz 3
public FileAccessI() throws IOException W&}R7a@:<~
{ d'kQE_y2.
this("",0); tu6c!o,@
} z++*,2F
%@G<B
\UGs_5OT
public FileAccessI(String sName,long nPos) throws IOException aIRCz=N
{ * ?rw'
oSavedFile = new RandomAccessFile(sName,"rw"); Xl2Fgg}#
this.nPos = nPos; y{s?]hLk
oSavedFile.seek(nPos); 1*[h$Z&H?
} E4HG`_cWb
u\ytiGO*
!0fpD'f!n
public synchronized int write(byte[] b,int nStart,int nLen) cA`R~o"
{ R5r )01
int n = -1; >UE_FC*u
try{ EW0H"YIC
oSavedFile.write(b,nStart,nLen); _wCp.[3?t
n = nLen; @GBS-iT3
} C"<l}
catch(IOException e) }7g\1l\
{ P@lExF*D1:
e.printStackTrace (); `T{{wty
} zr\I1v]?1#
l\ts!p4f$
hp%|n:.G
return n; 4M6o+WV
} dU3UCD+2y
@mNf(&
/.aZXC$]
} +AtZltM i
IW Lv$bPZ/
"7JO~T+v
/* S@z$,}Yc`<
**SiteInfoBean.java d\3L.5]X
*/ xQ* U9Wt;T
package NetFox; )T(xQ2&r4
R4_4FEo
w-AF5%gX
public class SiteInfoBean { m%+W{N4Wb
0 4x[@f`
?M;2H{KG:
private String sSiteURL; //Site's URL ^p|MkB?uM
private String sFilePath; //Saved File's Path FdKp@&O+1
private String sFileName; //Saved File's Name @%O"P9;s
private int nSplitter; //Count of Splited Downloading File `]FA} wC
f:B+R
.*r?zDV
public SiteInfoBean() 7F>5<Gv:-
{//nSplitter的缺省值为5 }C}~)qaZv+
//default value of nSplitter is 5 ,1Suq\ L
this("","","",5); c;&m}ImLe.
} X'TQtI
O9r3^y\>I
[j?n}D@L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U!XC-RA3 _
{ SWz+.W{KQ"
sSiteURL= sURL; e/r41
sFilePath = sPath; 6$4G&'J
sFileName = sName; ^IjKT
this.nSplitter = nSpiltter; fYuJf,I[f
#y&3`Nz3
j_L 'Ztu3
} ?NGM<nK;7
9Y&n$svB
fv5'Bl
public String getSSiteURL() w+=>b
{ 54JZEc
return sSiteURL; lV?rC z
} z. VuY3
YKJk)%;+w
<dV|N$WV
public void setSSiteURL(String value) VSx[{yn
{ 1U;je,)
sSiteURL = value; |[>`3p"&
} o*_[3{FU
^W eE%"
al F*L
public String getSFilePath() GLB7h9>
{ 9jDV]!N4
return sFilePath; +6B(LPxgP
} \tye:!a?;@
I?G m
H~i+:X=I
public void setSFilePath(String value) 8v8?D8\=|
{ 5,:>.LRA
sFilePath = value; YjdCCju
} b*',(J94
RgHPYf{
]!d #2(
public String getSFileName() 'VS!<
{ =<YG0K
return sFileName; beRpA;
} .5p"o-:D
f>s3Q\+
!e?=I
public void setSFileName(String value) "A~\$
{ awB1ryrOF
sFileName = value; 4'Z=T\:
} .2q7X{4=
b2aPo M=
3!_y@sWx
public int getNSplitter() elG<\[
{ U; JZN
return nSplitter; \U(qv(T
} F-R4S^eV
ZN~:^,PO/
"^fcXV9Wp
public void setNSplitter(int nCount) H{VVxj
{ .}&bE1
nSplitter = nCount; dGt;t5AnV
} f>k]{W Y
} G#t!{Q}8
&#;vR0O
oTS*k: C'
/* luACdC
**Utility.java Obgn?TAVX
*/ N\ChA]Ck
package NetFox; a[Ah
q(p]6Ha|
H5'/i;
public class Utility { 'h53:?~
z|^:1ov,
3,DUT{2
public Utility() :aI[ lZ
{ 1Jg&L~Ws"
y2;uG2IS_g
yDg`9q.ckm
} eU&[^
]dHU
//线程睡眠 .t*MGUg
public static void sleep(int nSecond) FloCR=^H
{ qPDe;$J)
try{ }enm#0Ha
Thread.sleep(nSecond); PN:/lIO
} H:Y?("k
catch(Exception e) @W[`^jfQ
{ f]W$4f{
e.printStackTrace (); 62TWqQ!9d
} 15U]/?jv8
} ZX[@P?A+-
/Fy2ZYs,`8
//日志 HR]*75}e
public static void log(String sMsg) Yj)H!Cp.xD
{ 0}}b\!]9
System.err.println(sMsg); xTiC[<j
} f40xS7-Q0
R8O;8c?D
1vk&;
public static void log(int sMsg) i%w[v_j
{ %MGbIMpY
System.err.println(sMsg); 4WU%K`jnXb
} J:LwO
} mj:X'BVA
04g=bJ
i,|2F9YH
/* `d]D=DtH
**TestMethod.java BQ!v\1'C
*/ P7np -I*
package NetFox; x8 :
bwN>E+
8WU_d`DF
public class TestMethod { V|[Y9<*
uv,&/,;S
TK^9!3
public TestMethod() :'p+Ql~c
{ ///xx/weblogic60b2_win.exe K,_d/(T4
try{ ;|7]%Z}%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P(AcDG6K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |rW,:&;
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1~rZka[s
fileFetch.start(); R@zl?>+
} xNDX(_U>\
catch(Exception e){e.printStackTrace ();} f/+UD-@%m
OwRH :l
o^HzE;L}
} L-SWs8
{}x{OP
~Y;_vU
public static void main(String[] args) "A?&`}%
{ Z ,4G'[d
new TestMethod(); Q|T9tc->
} tA;#yM;
} 4FLL*LCNX
点击下载更多相关资料