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)); Wy7w zt
} ;Go^)bN ;
for(int i=0;i<nEndPos.length-1;i++) U?:P7YWy
{ ga%\n!S
nEndPos = nStartPos[i+1]; ,GYQ,9:
} IUv#nB3
nEndPos[nEndPos.length-1] = nFileLength; VnsV&cx
} b-VygLN
} mYgfGPF`
ErK1j
/_qq(,3
//启动子线程 ~#3{5* M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >z\IO
for(int i=0;i<nStartPos.length;i++) (V6bX]<
{ eW(pP>@k,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6AAvsu:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fAULuF
nStartPos,nEndPos,i); G)?*BH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }MRgNr'k
fileSplitterFetch.start(); X#&5?oq`
} )sm9%|.&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )-3~^Y#r_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'lZlfS:Z8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Df4O~j$U"s
nEndPos = " + nFileLength); G7 UUx+X
// fileSplitterFetch[nPos.length-1].start(); A?lLK&*
3$!QP N
:.+w'SEn4M
//等待子线程结束 '0+I'_(
//int count = 0; );.$`0
//是否结束while循环 uBbQJvL
boolean breakWhile = false; >j=ZB3yZ
`nyz,
utZI'5i
while(!bStop) >`x|E-X"
{ l7VO8p]y[R
write_nPos(); 0vqH-)}
Utility.sleep(500); Z{^!z
breakWhile = true; |URfw5Hm
BjH|E@z
=T[P
for(int i=0;i<nStartPos.length;i++) Wa^Wn +r
{ s=jmvvs_V}
if(!fileSplitterFetch.bDownOver) %Y ZCdS
{ UJ}}H}{
breakWhile = false; "^$Ht`p[
break; ;I*t5{
} \7LL neq
} h2zSOY{su
if(breakWhile) N9/k`ZGC
break; mx}5":}
RkG?R3e
*,X)tZ6VX
//count++; .@&FJYkLYi
//if(count>4) 7-B|B{]
// siteStop(); 55O}SUs!P
} %.$!VTO"
6Mc&=}bV
KcV"<9rE
System.err.println("文件下载结束！"); lD$s, hp
} la{?&75]
catch(Exception e){e.printStackTrace ();} 9\!&c<i=
} }` 3-
WDY\Fj
=r/K#hOR\J
//获得文件长度 bnfeZR1m_
public long getFileSize() TYuP EVEXZ
{ h{mzYy}b
int nFileLength = -1; 9q?knMt
try{ -J63'bb7oi
URL url = new URL(siteInfoBean.getSSiteURL()); TE&E f$h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l#cVQ_^"
httpConnection.setRequestProperty("User-Agent","NetFox"); v>K|hH
? /!Fv/
M %zf?>])
int responseCode=httpConnection.getResponseCode(); Ut~YvWc9
if(responseCode>=400) w31O~Ve
{ qsp3G7\'=
processErrorCode(responseCode); &H# l*
return -2; //-2 represent access is error A(&\wd
} 3\ajnd|
EUw4$Jt^p
fAStM:
String sHeader; 53uptQ{
<6]Hj2
bzpi7LKN
for(int i=1;;i++) u*l>)_HD
{ ,eebO~7vB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0D4 4
//Utility.log(in.readLine()); TCzz]?G]la
sHeader=httpConnection.getHeaderFieldKey(i); ;t7F%cDA
if(sHeader!=null) {C`M<2W]
{ a.u{b&+9
if(sHeader.equals("Content-Length")) 3 a(SmM:
{ q:up8-LAr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o$bQ-_B`
break; mKM[[l&A
} 2O(k@M5E?
} CNuE9|W(vI
else f(}&8~&
break; d+P<ce2G
} .))k
} m?Jnb\0
catch(IOException e){e.printStackTrace ();} e+Mm!\;`
catch(Exception e){e.printStackTrace ();} vIi&D;
7 HL Uk3
+:#g6(P]
Utility.log(nFileLength); hBZh0xy
l+(B~v
o}36bi{
return nFileLength; QncjSaEE
} +7"UF) ~k
-[=@'NP
31g1zdT!
//保存下载信息（文件指针位置） zxv y&
private void write_nPos() r+]a
{ 2DZ&g\|
try{ C>l (4*S
output = new DataOutputStream(new FileOutputStream(tmpFile)); muK)Yw[#N
output.writeInt(nStartPos.length); 2#`d:@r
for(int i=0;i<nStartPos.length;i++) ,+Ya'4x
{ dg N#"
// output.writeLong(nPos); B 4e}%
output.writeLong(fileSplitterFetch.nStartPos); kYS\TMt,C
output.writeLong(fileSplitterFetch.nEndPos); tr 8Q{
} q<g!bW%
output.close(); Mv%B#J
} [eF|2:
catch(IOException e){e.printStackTrace ();} 48GaZ@v
catch(Exception e){e.printStackTrace ();} jN+2+P%OL
} 9mv6
)A;jBfr
S@L%X<Vm
//读取保存的下载信息（文件指针位置） 3v~}hV/RUy
private void read_nPos() C5^N)-]"
{ %eu_Pr6X
try{ n<[H!4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xUs1-O1i
int nCount = input.readInt(); Im`R2_(]
nStartPos = new long[nCount]; Bm^8"SSN
nEndPos = new long[nCount]; # WL5p.
for(int i=0;i<nStartPos.length;i++) ^6,}*@
{ }Oy/F
nStartPos = input.readLong(); BI6`@}%7>
nEndPos = input.readLong(); PPtJ/ }\
} ,S3uY6,
input.close(); 7mS_Cz+cB
} `MMZR=LA
catch(IOException e){e.printStackTrace ();} u7u1lx>S
catch(Exception e){e.printStackTrace ();} 2f0_Xw_V_
} =~j S
,!g%`@u
Dmv@ljwO
private void processErrorCode(int nErrorCode) <</ Le%
{ Ej64^*
System.err.println("Error Code : " + nErrorCode); wpPCkfPyL
} ns[Q %_
3sq(FsT
Gj([S17\0:
//停止文件下载 IGtqY8
public void siteStop() |G]M"3^
{ e!~x-P5M`
bStop = true; -J=N
for(int i=0;i<nStartPos.length;i++) T8rf+B/.L
fileSplitterFetch.splitterStop(); /SZg34%
%phv<AW
Fs EPM"&?h
} b}#ay2AR
} |CFTOe\q
//负责部分文件的抓取 i^'Uod0d.
**FileSplitterFetch.java L>EC^2\
*/ Mw+8p}E
package NetFox; }PDNW
wmr8[n&c
cU'^ Ja?%
import java.io.*; RI%ZT
import java.net.*; x GHS
77ID 82
%v(\;&@
public class FileSplitterFetch extends Thread { _:tisr{
G}b LWA
Ll L8Q
String sURL; //File URL )cy_d!
long nStartPos; //File Snippet Start Position isP4*g&%x
long nEndPos; //File Snippet End Position G6b\4}E
int nThreadID; //Thread's ID to
boolean bDownOver = false; //Downing is over "sf]I[a
boolean bStop = false; //Stop identical |H4/a;]~
FileAccessI fileAccessI = null; //File Access interface OW12m{
5b9>a5j1;
$iA`_H`W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x-_!I>l&
{ H+>l][
this.sURL = sURL; 3wBc`vJ!
this.nStartPos = nStart; F*_mHYa;
this.nEndPos = nEnd; {]}}rx'|P
nThreadID = id; /EOtK|E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m3k}Q3&6Z
} U&6!2s-
.jhuC#x{/
TCSm#?[B
public void run() 5s>$
{ wL2d.$?TEg
while(nStartPos < nEndPos && !bStop) SLc6]?
{ /R< Q~G|\
Mp~E$f
1(Kd/%]{
try{ AG#5_0]P~
URL url = new URL(sURL); %cD7}o:u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e/WR\B'1
httpConnection.setRequestProperty("User-Agent","NetFox"); "~4ULl<i'
String sProperty = "bytes="+nStartPos+"-"; %/H
httpConnection.setRequestProperty("RANGE",sProperty); M[0@3"}}
Utility.log(sProperty); d;ElqRC&
!V.'~xj
p3*}!ez4
InputStream input = httpConnection.getInputStream(); +gTnq")wnI
//logResponseHead(httpConnection); iuq-M?1
}@V(y9K
v"L<{HN
byte[] b = new byte[1024]; ,|b<as@X
int nRead; aU2O5z&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !h2ZrT9 _
{ 2-u>=r0L
nStartPos += fileAccessI.write(b,0,nRead); S@zsPzw
//if(nThreadID == 1) fAfsKO*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i7})VDsZ
} H;}V`}c<`
9xC,i )
V$-IRdb
Utility.log("Thread " + nThreadID + " is over!"); y&A*/J4P
bDownOver = true; _ EHr?b2
//nPos = fileAccessI.write (b,0,nRead); &D uvy#J
} kVQKP U
catch(Exception e){e.printStackTrace ();} [X=-x=S,
} 1A">tgA1
} _5.^A&Y*
z:|4S@9
KQ xKU?b1
//打印回应的头信息 :Cw|BX@??U
public void logResponseHead(HttpURLConnection con) xe|o(!(
{ Q,Hw@w<1
for(int i=1;;i++) YQiTx)_
{ 8\`]T%h
String header=con.getHeaderFieldKey(i); 3*3WO,9
if(header!=null) #~q{6()e:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); myFjw@
Utility.log(header+" : "+con.getHeaderField(header)); Tl%#N"
else WtFv"$V
break; FlRbGg^
} @X"p"3V
} I2qC,Nkk
IBC P6[
G{i}z^n
public void splitterStop() !t{3IE
{ r@H<@Vuc
bStop = true; %7Z_Hw
} fnG&29x
,Zb]3
Ja|! fT
} Z'>Xn^
T c4N\Cy
#]oVVf_
/* vL`wn=
**FileAccess.java c</d1xT
*//文件访问(定位，写) N't*eCi
package NetFox; amK?LDf]
import java.io.*; kV(}45i]s
!%_Z>a
V{O,O,*
public class FileAccessI implements Serializable{ >o>r@;
n@mWBUM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X5cl'J(j9
RandomAccessFile oSavedFile; 4$+1jjC]>~
long nPos; 7KnZ
M])Y|}wv8
"@RLS~Ej
public FileAccessI() throws IOException j#"?Oe{_1
{ Pq>r|/~_
this("",0); p\wE})mu
} )dbi
DmM<Kkg.J
ns9iTU)
public FileAccessI(String sName,long nPos) throws IOException ce\]o^4
{ fmXA;^%
oSavedFile = new RandomAccessFile(sName,"rw"); rJ4O_a5/
this.nPos = nPos; TggM/@k
oSavedFile.seek(nPos); x1W<r)A )r
} <->Nex
mVg-z~44T
^]3Y11sI
public synchronized int write(byte[] b,int nStart,int nLen) >c*}Do{lG
{ QM=M<~<Voh
int n = -1; ^&MMtWR
try{ N W :_)1
oSavedFile.write(b,nStart,nLen); /L'r L
n = nLen; .8S6;xnkC
} w7cciD|
catch(IOException e) "jH=O(37
{ bYGK}:T8U
e.printStackTrace (); iY1%"x
} <UOx>=h
m!3b.2/h
1P:r=Rt/
return n; >KmOTM<{
} 2`tdH|Z`
k3h,c;
I *YO
} :'9%~q.D4
47.c
Veo:G{
/* q(4W/y
**SiteInfoBean.java `mXbF
*/ #5-5N5-1
package NetFox; &4Q(>"iL4
Dj}n!M`2I
bmgK6OyVR
public class SiteInfoBean { aT1T.3 a
4bLk+EY4A
2A7g}V
private String sSiteURL; //Site's URL qP{S!Z(
private String sFilePath; //Saved File's Path 7^7Rk
private String sFileName; //Saved File's Name wNMgY
private int nSplitter; //Count of Splited Downloading File mX3~rK>@~
_PD RUJ
4A6D>ChB'E
public SiteInfoBean() 9v>BP`Mg
{//nSplitter的缺省值为5 v-M3/*
//default value of nSplitter is 5 NSH20$A<
this("","","",5); WBD e`
} 2c`m8EaJ
mL/]an@Y
wQbN5*82
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iU3)4(R
{ q$FwO"dC
sSiteURL= sURL; b*Ny
sFilePath = sPath; ],CJSA!5F
sFileName = sName; u=NpL^6s<
this.nSplitter = nSpiltter; 7zo)t1H1
dzJ\+ @4
y3l3XLI*b
} '{=dEEi
^%l~|w
V?AHj<
public String getSSiteURL() ?&#z3c$}
{ ^% y<7>%
return sSiteURL; "8MG[$Y
} E +\?|q !T
w{uqy]
/*3[9,
public void setSSiteURL(String value) 0"q_c-_Bg
{ xxxM
sSiteURL = value; /MFy%=0l
} MG ,exN @
E^uau=F
Ei!t#'*D<
public String getSFilePath() o=i)s2
{ !u~h.DrvZ
return sFilePath; k^3 ?Z2a
} FlJ(V
PZ5BtDm
i*34/
public void setSFilePath(String value) |Y'xtOMX
{ E~oQ%X~
sFilePath = value; ly`p)6#R=
} U-.?+`
jP'.a. ^o$
VsS.\1
public String getSFileName() 3/a$oO
{ 9^l[d<
return sFileName; I)$`@.
} s@C KZ`
V[D[MZ
8joJe>9VJ
public void setSFileName(String value) 4k'2FkDA
{ gM=oH
sFileName = value; {2kw*^,l
} =6j4_+5mnH
=L_L/"*rel
-:9E+b
public int getNSplitter() fsc^8
{ #PYTFB%
return nSplitter; A#9@OWV5f
} F@Bh>Vb
(WT0j
`jY*0{
public void setNSplitter(int nCount) v=Ep
{ S-^y;#=
nSplitter = nCount; RB1c!h$u
} [\N,ow,n
} |a@$KF$
#;. tVo I
Bvx%|:R
/* ]p3hq1u3&
**Utility.java =\s(v-8
*/ x:8xGG9
package NetFox; dP0!?J Y
@W3fKF9*R
;p~@*c'E
public class Utility { 75vd ]45as
\ B 0xL,o<
x9r5 ;5TI
public Utility() @]lKQZ^2&
{ I^ W
@Tmqw(n{
2d+IROA
} kJIKULf
G`E%uyjG$j
//线程睡眠 }8 A]
public static void sleep(int nSecond) Er} xB~<t
{ F;yq/e#Q
try{ M`HXUA4
Thread.sleep(nSecond); 0hcrQ^BB!b
} h$|K vS
catch(Exception e) #:L|-_=a
{ t6_6Bl:
e.printStackTrace (); j['Z|Am"l
} 4\<[y]pv
} 'wz*GMGWC
F>&Q5Kl R
//日志 > taT;[Oa
public static void log(String sMsg) f33'2PYl
{ NZYtA7
System.err.println(sMsg); 3JEH sYxs
} N8}R<3/
)zI<C=])"
(:].?o
public static void log(int sMsg) 9I=J#Hi|+
{ Qpiv,n
System.err.println(sMsg); ~}w(YQy=y
} UZMo(rG.]{
} fDp_W1yH
A_T-]YQ
0}hN/2}&
/* _WtX8
**TestMethod.java 4JFi|oK0H
*/ D|9C|q
package NetFox; EonZvT-D=
NWNH)O@
@)m[:n
public class TestMethod { F}<&@7kF
6Z ~>d;&9
lYv :
public TestMethod() ~xGWL%og
{ ///xx/weblogic60b2_win.exe 39S}/S)
try{ wJ1qJ!s@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `hM`bcS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5*[zIKdt2
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7on$}=%
fileFetch.start(); $%`OJf*k
} 91E!4t}I
catch(Exception e){e.printStackTrace ();} ruS/Yh
g?A4C`l6iy
)J<Li!3
} |Q`}a %
zOLt)2-<
@7 &rDZ
public static void main(String[] args) '|':W6m,
{ 0?BT*
new TestMethod(); 8II-'%S6q
} $n(?oyf
} z(g4D!
点击下载更多相关资料