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)); qh&K{r*T
} 6Edqg
for(int i=0;i<nEndPos.length-1;i++) QU#/(N(U#T
{ '8Gw{&&
nEndPos = nStartPos[i+1]; R-h7c!ko
} Tl1?5
nEndPos[nEndPos.length-1] = nFileLength; ~]yqJYiid^
} my} P\r.
} L`Ic0}|lzy
Z7f~|}
G6J3F
//启动子线程 ILVbbC`D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X:e'@]Z)?
for(int i=0;i<nStartPos.length;i++) N&GcWcq
{ 3{c&%F~!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *FAg^G&1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N&ddO-r[s
nStartPos,nEndPos,i); WI6er;D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K{iayg!k
fileSplitterFetch.start(); *1%g=vb
} {Ise (>V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \agC Q&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?3|ZS8y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eU12*(
nEndPos = " + nFileLength); )l"0:1Ig
// fileSplitterFetch[nPos.length-1].start(); S4(IYnwN
S_QDYnF)`
+amvQ];?Q8
//等待子线程结束 z7K?rgH
//int count = 0; O@$hG8:
//是否结束while循环 3gM{lS}h#
boolean breakWhile = false; qJK^i.e
2cDC6rul
Wu}Co
while(!bStop) ._R82gy
{ "d#s|_n,d)
write_nPos(); #zQkQvAT9
Utility.sleep(500); rvG qUmSUs
breakWhile = true; cK258mY
NMDNls&)k
O]Hg4">f
for(int i=0;i<nStartPos.length;i++) ?y '.sQ
{ vbFAS:Y:+
if(!fileSplitterFetch.bDownOver) ~ 52
{ dqe_&C@*O
breakWhile = false; ^g0 Ig2'
break; E`s_Dr}K
} pQ/:*cd+M
} L fi]s
if(breakWhile) }E=kfMu
break; tyDtwV|
)CmuC@ Q"
m0edkt-x
//count++; OYzJE@r^
//if(count>4) ZN)/doK
// siteStop(); SB;Wa%
} >}I}9y+
}+B7C2_\
f&`*x t/
System.err.println("文件下载结束！"); \?g%>D:O;
} (r|T&'yK
catch(Exception e){e.printStackTrace ();} 7q?YdAUz
} < d]|5
kal8k-$#
s=$7lYX
//获得文件长度 nqH^%/7)A@
public long getFileSize() dOhV`8l
{ -`RJk(
int nFileLength = -1; 0{,zE
try{ s%:fB(
URL url = new URL(siteInfoBean.getSSiteURL()); y>OZ<!`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GWW@8GNI
httpConnection.setRequestProperty("User-Agent","NetFox"); zZxP= c
T'V(%\w
V":BAn
int responseCode=httpConnection.getResponseCode(); J!H5{7.efN
if(responseCode>=400) w(yU\ N
{ 08f~vw"
processErrorCode(responseCode); -3V~YhG
return -2; //-2 represent access is error i`Yf|^;@2>
} b'OO~>86
!69^kIi$
1D`RR/g&
String sHeader; {7wvC)WW
ky#6M? \
e\dT~)c
for(int i=1;;i++) sV6A& Aw
{ w0IB8GdF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y(R*Z^c}d,
//Utility.log(in.readLine()); !G,$:t1-=V
sHeader=httpConnection.getHeaderFieldKey(i); ^Pf&C0xXv
if(sHeader!=null) gv,T<A?Z2
{ yI%> w4Z
if(sHeader.equals("Content-Length")) w?*KO?K
{ WU4i-@Bm8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w(U/(C7R
break; YfalsQ8
} ? 1{S_
} jysV%q 3
else ^ZlV1G;/W@
break; Rf^cw}jU
} ""+*Gn7^8
} U,M,E@
catch(IOException e){e.printStackTrace ();} NQJqS?^W&M
catch(Exception e){e.printStackTrace ();} :6/OU9f/R
#R8l"]fxr?
L1xD$wl
Utility.log(nFileLength); iK]g3ew|
^zJ.W
OW}A48X[+
return nFileLength; StL[\9~:
} gB(W`:[
9O Q4\
Ib\G{$r
//保存下载信息（文件指针位置） kn"x[{d
private void write_nPos() jq]"6/xxb
{ GN9_ZlC
try{ 9/M!S[N9
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?>8zU;Aj
output.writeInt(nStartPos.length); #[W[|m
for(int i=0;i<nStartPos.length;i++) UT~2}B9fc
{ E,fp=.
// output.writeLong(nPos); @qDrTH]5
output.writeLong(fileSplitterFetch.nStartPos); @,&m`qzd+
output.writeLong(fileSplitterFetch.nEndPos); @>@Nug2
} QL2y,?Mz7
output.close(); B|=maz:_
} aTm.10{^
catch(IOException e){e.printStackTrace ();} weV#%6=5\
catch(Exception e){e.printStackTrace ();} pCUOeQL(
} zrO|L|F&P
ss{=::#
uq%3;#[0
//读取保存的下载信息（文件指针位置） I0vnd7
private void read_nPos() J\+gd%
{ /&:9VMMj
try{ .K1E1Z_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BDRVT Y(s
int nCount = input.readInt(); Vk_&W.~
nStartPos = new long[nCount]; t)Q@sKT6
nEndPos = new long[nCount]; Y^Q|l%Qrb
for(int i=0;i<nStartPos.length;i++) ?1:/ 6
{ SQU%N
nStartPos = input.readLong(); ]~Vu-@ /}
nEndPos = input.readLong(); #ljg2:I+
} 9:i,WJO
input.close(); *.c9$`s
} (I ds<n"
catch(IOException e){e.printStackTrace ();} K=?F3tX^
catch(Exception e){e.printStackTrace ();} ]C6[`WF
} idS RWa
QeJ.o.m{
%OW9cqL>l
private void processErrorCode(int nErrorCode) fsc~$^.~\
{ DIp:S&q2
System.err.println("Error Code : " + nErrorCode); "ue$DyN
} #Rx"L&3Ue
<lmJa#
So*Wk "
//停止文件下载 @1&;R
public void siteStop() Fg\| e%
{ \e8*vos
bStop = true; s]vJUC,s
for(int i=0;i<nStartPos.length;i++) Sje0:;;|
fileSplitterFetch.splitterStop(); HL}~W}!j
% rY8
>^f)|0dn)E
} Rfc&OV
} %Fg8l{H3
//负责部分文件的抓取 ,e FQ}&^A
**FileSplitterFetch.java P"uHtHK
*/ 8H#c4%by)
package NetFox; Owpg]p yVD
,PMb9O\B
!8@rK$DB
import java.io.*; E}' d,v#Z{
import java.net.*; n~ >h4=h
+F~0\#d
&<V_[Wh"
public class FileSplitterFetch extends Thread { T[XP\!z]B!
\_Kt6=
"gvw0)
String sURL; //File URL h@,e`Z
long nStartPos; //File Snippet Start Position IO!1|JMr6
long nEndPos; //File Snippet End Position )=E~CpKV
int nThreadID; //Thread's ID ,J(5@8(>a
boolean bDownOver = false; //Downing is over T$^>Fiz{Se
boolean bStop = false; //Stop identical wz*A<iU
FileAccessI fileAccessI = null; //File Access interface #}!>iFBcH
r d6F"W
Ls>u`hG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8yWu{'G
{ 5\w=(c9A
this.sURL = sURL; 8f,'p}@!d
this.nStartPos = nStart; mo#0q&ZQ
this.nEndPos = nEnd; HA9Nr.NqC@
nThreadID = id; =tc`:!$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |aS~"lImh
} Cj !i)-
<duBwkiG
/iTUex7T
public void run() >1r[]&8
{ B221}t
while(nStartPos < nEndPos && !bStop) |)?aH2IL
{ KZ!N{.Jk
1t[;`iZ
fATA%eA8;
try{ H6ky)kF&
URL url = new URL(sURL); HZDaV&)@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {yHB2=nI
httpConnection.setRequestProperty("User-Agent","NetFox"); 0^&(u:~
String sProperty = "bytes="+nStartPos+"-"; RO%tuU,-
httpConnection.setRequestProperty("RANGE",sProperty); K=c=/`E
Utility.log(sProperty); c8-69hb?
sWsG,v_
-eR!qy:.]5
InputStream input = httpConnection.getInputStream(); DrCWvpudd
//logResponseHead(httpConnection); :otY;n-
[W9e>Nsp0
V5u}C-o
byte[] b = new byte[1024]; D/S>w(=
int nRead; M9Nk=s! 3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qIDWl{b<
{ hY.e[+
nStartPos += fileAccessI.write(b,0,nRead); jSie&V@px
//if(nThreadID == 1) /o|PA:6J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xTJSr2f
} #a(%(k S
M<A;IOpR+
`J>E9p<
Utility.log("Thread " + nThreadID + " is over!"); '&-5CpDUs
bDownOver = true; #QTfT&m+G}
//nPos = fileAccessI.write (b,0,nRead); \!UF|mD^tG
} jr,&=C(
catch(Exception e){e.printStackTrace ();} DJViy
} "ep`
} ASKAgU"h
.'^6QST
YPha9M$AgU
//打印回应的头信息 K0O-WJ
public void logResponseHead(HttpURLConnection con) `Di ^6UK(
{ fiE>H~
for(int i=1;;i++) G2CZwm{/f
{ FJsK5-
String header=con.getHeaderFieldKey(i); E!zd(
if(header!=null) %\}dbYS '
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |rE!
Utility.log(header+" : "+con.getHeaderField(header)); r,2Xu
else "x#]i aDjf
break; L_THU4^j
} mL:m;>JJ n
} DKy>]Hca
~\IF9!
$ \Q<K@{
public void splitterStop() /h}PEu3y
{ I.^X2
bStop = true; eJU;*] xfH
} y|q@;*rGNa
jlu`lG*e&
(NH8AS<
} 6=ZRn gQ
Q`.'-iq
xwTijSj
/* `z9)YH
**FileAccess.java N]1V1c$G*
*//文件访问(定位，写) 1YOg1 n+k
package NetFox; NuC-qG#
import java.io.*; = EQN-{#
w^06z,
On#;)35M
public class FileAccessI implements Serializable{ L;/9L[s,
LP.HS'M~u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sm$p\ORa
RandomAccessFile oSavedFile; h5L=M^z!>
long nPos; !]$V9F{K
WGH%92
U7^7/s/.
public FileAccessI() throws IOException 9#v-2QY
{ F>(qOH.I
this("",0); Err4 %-
} <Z{vC
:PgF
7JbY}@
public FileAccessI(String sName,long nPos) throws IOException =nJ{$%L\x,
{ Z5((1J9
oSavedFile = new RandomAccessFile(sName,"rw"); jCU=+b=
this.nPos = nPos; \Dn&"YG7
oSavedFile.seek(nPos); z%OuI 8"'
} R=!kbBK>\
Q;4}gUmI$
FoE|Js
public synchronized int write(byte[] b,int nStart,int nLen) xDR9_
{ 60xa?8<cg
int n = -1; K@B" ]6
try{ <^d!Vzr]
oSavedFile.write(b,nStart,nLen); cNe0x2Z$?
n = nLen; L ;6b+I
} hS4.3]ei
catch(IOException e) dZPW2yf
{ x>}B#
e.printStackTrace (); )VNM/o%Q
} lc]V\'e
z)}3**3'y
oFWt(r
return n; +`ai1-vw
} ZAMeqPt
DW#Bfo
,Kuk_@(}5~
} W%TQYR
1Fv8T'
TYYp"wx
/* G 0hYFc u
**SiteInfoBean.java @&;(D!_&
*/ Z+ixRch@-s
package NetFox; v2d<o[[C
?-pi,O~(p
BWWq4mdb{
public class SiteInfoBean { hw;0t,1
'iJDWxCD
=/[ltUKs:a
private String sSiteURL; //Site's URL JjQ8|En
private String sFilePath; //Saved File's Path T'E] i!$
private String sFileName; //Saved File's Name 2+z1h^)W
private int nSplitter; //Count of Splited Downloading File )B6# A0
1!vPc93 $$
R,%_deV\(
public SiteInfoBean() YydA6IK4
{//nSplitter的缺省值为5 ?]^zD k@~
//default value of nSplitter is 5 @<2d8ed
this("","","",5); R~)ybf{
} nP<S6:s:
K}x_nW
#<4--$Xo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ylu2R0] (
{ t-WjL@$F/
sSiteURL= sURL; tR1FO%nC
sFilePath = sPath; wxE?3%.j\
sFileName = sName; {(4# )K2g%
this.nSplitter = nSpiltter; Wbe0ZnM]
C}q>YRubZ
-ey)J +?t
} TjxA#D)
L1sqU-gt
$/+so;KD
public String getSSiteURL() } ~| k
{ ^-hErsK
return sSiteURL; @D~B{Hg
} ,9d9_c.T
/%!~x[BeJ>
e'34Pw!m
public void setSSiteURL(String value) Pe}PH I
{ yYY Nu`
sSiteURL = value; L;S}s, 2x
} qy ,"X)^#
?n.)&ZIx0
qNxB{0(D
public String getSFilePath() VevNG*
{ Fi4UaJ3K
return sFilePath; rFey4zzz
} pLnB)z?
h./P\eDc
yoQ\lk
public void setSFilePath(String value) C`QzT{6!
{ =\Iu$2r`
sFilePath = value; z<B CLP
} ='}#`',
RP! X8~8
)u*^@Wo
public String getSFileName() GKZN}bOm\
{ ?iv=53<c#
return sFileName; :HRT 2I
} y(5:}x&E
jZd}OC<
n*<v]1
public void setSFileName(String value) .po>qb6
{ o_f-GO
sFileName = value; e\F}q)_
} G>w+#{(
"$|Zr
BtsdeLj|
public int getNSplitter() vN65T$g7
{ n-J2/j
return nSplitter; dz-y}J11
} t>xd]ti
(RE2I
Q9c)k{QZ
public void setNSplitter(int nCount) #H~_K}Ks
{ \S ."?!U
nSplitter = nCount; booRrTS
} 6o=G8y
} gl8Ib<{
Q`ME@vz
S_b/DO
/* Xj@+{uvQB
**Utility.java `)Ky0&?
*/ \+m$
package NetFox; *jITOR!uF`
pK}=*y~$
8Lz]Z h=ZU
public class Utility { B{MaMf)
V5p0h~PK
jVWK0Zba
public Utility() qf#)lyr<D6
{ },@``&e
5MF#&v
C&<~f#lB
} pHC/(6?
.c+9P<VmC}
//线程睡眠 QkQ!Ep(
public static void sleep(int nSecond) :Ht;0|[H
{ 28I^$> [
try{ Z7a945Jd
Thread.sleep(nSecond); ldqLM
} FwG!>
catch(Exception e) <RXwM6G2
{ pQa:pX
e.printStackTrace (); ' cIEc1y
} /7"I#U^u/
} [k<1`z3
{tiKH=&J
//日志 f&KdlpxKv
public static void log(String sMsg) ,$lemH1d
{ i=S~(gp
System.err.println(sMsg); "ju'UOcS/
} iE].&>w
F@YKFk+a
WFTvOFj
public static void log(int sMsg) G`0V)S
{ viX +|A4gJ
System.err.println(sMsg); g>JLDQdc
} K.~q+IYP[
} qv*7K@
@N@F,~[RR2
3gEMRy*+
/* 9=`Wp6Gmn
**TestMethod.java p@ NaD=9
*/ pzZk\-0R
package NetFox; oUZoj2G1
2JGL;U$
EgjR^A1W2
public class TestMethod { XvTCK>1
hX:"QXx
\ 0W!4D
public TestMethod() U8$4 R,+
{ ///xx/weblogic60b2_win.exe Mkxi~p%<r
try{ WKfkKk;G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cVnJ^*Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /]^#b
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^D%Za'
fileFetch.start(); zP\7S}p7%
} )!:sFa 1
catch(Exception e){e.printStackTrace ();} M5357Q
Z @ dC+0[=
')Y'c
} "qz3u`[o
'a6<ixgo0
O^Q7b7}y
public static void main(String[] args) nI.x
{ :Qt
new TestMethod(); 8,P- 7^
} dP?Ge}
} fxaJZz$o
点击下载更多相关资料