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)); skeXsls
} H!81Pq~
for(int i=0;i<nEndPos.length-1;i++) V49[XX
{ c+bOp 05o-
nEndPos = nStartPos[i+1]; 6a%dq"5 +
} FRR`<do5$,
nEndPos[nEndPos.length-1] = nFileLength; { ML)F]]
} }u `~lw(Z
} ;+Mee^E>!
% k}+t3aF
'ZXd|WI
//启动子线程 )_H>d<di
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Z<V?SFOK
for(int i=0;i<nStartPos.length;i++) q qFN4AO
{ Q$B\)9`v[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ? JliKFD%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T:G8xI1 P
nStartPos,nEndPos,i); 3yXSv1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sq;nUA=
fileSplitterFetch.start(); 4r-CF#o
} .1@8rVp7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TEEt]R-y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ndE"v"_H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LV6BSQyQ
nEndPos = " + nFileLength); #FwTV@
// fileSplitterFetch[nPos.length-1].start(); h)o5j-M>4
G,,7.%eib=
a?NoNv)&
//等待子线程结束 =kiDW6 JJU
//int count = 0; ./r#\X)dc
//是否结束while循环 _]"uq/UWp
boolean breakWhile = false; ?Dn 6
k "Qr
j3$\+<m]
while(!bStop) Ae3=o8p
{ Pg%k>~i
write_nPos(); 3$#=*Zp
Utility.sleep(500); +j!$88%Z{
breakWhile = true; $Ao iH{f
yM`QVO!;
e'MLLC[
for(int i=0;i<nStartPos.length;i++) OY'6~w9
{ tg#d.(
if(!fileSplitterFetch.bDownOver) Y3M"a8e'
{ 9'I$8Su
breakWhile = false; RkTO5XO
break; MWHzrqCA
} ZhnRsn9
} FrL ;1zt
if(breakWhile) F*{1, gb
break; mO0a: i!
%;-r->
L`@)*x)~R
//count++; !IAd.<,
//if(count>4) yGZsPQIaV
// siteStop(); p/4}SU
} Q?WgGE4>
ELa:yIl0
'ngx\Lr
System.err.println("文件下载结束！"); 7a5G,C#QQ
} _fmOTz G
catch(Exception e){e.printStackTrace ();} b8~7C4
} \ x>#bql+
{+@M!
/`H{n$
//获得文件长度 G}NT[
public long getFileSize() bQBYzvd
{ yh{Wuz=T
int nFileLength = -1; 3+tr_psH
try{ m`B.3
URL url = new URL(siteInfoBean.getSSiteURL()); US2Tdmy@05
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &?(472<f**
httpConnection.setRequestProperty("User-Agent","NetFox"); daN#6e4Z+;
nX\Q{R2
biy[h3b
int responseCode=httpConnection.getResponseCode(); N3SB-E+
if(responseCode>=400) F2WMts
{ i8 fUzg)
processErrorCode(responseCode); +~l`rJ
return -2; //-2 represent access is error @(I)]Ca%O
} snti*e4"V
Ua\<oD79]
yIG*
String sHeader; 0OF]|hH
nA 5-P}
LAcK%
for(int i=1;;i++) OdHl)"#
{ MB3 0.V/\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,?(IRiq%
//Utility.log(in.readLine()); Wt $q{g{C
sHeader=httpConnection.getHeaderFieldKey(i); %o4HCzId<
if(sHeader!=null) \L4+Dv<z
{ /aX#j`PrH
if(sHeader.equals("Content-Length")) |\] _u 3
{ vm4q1!!(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /Zm5fw9
break; `@#,5S$ E
} q+)csgN
} UukHz}(E
else ~RIn7/A
break; 1EcXvT=
} C$#X6Q!,
} [>xGynU0
catch(IOException e){e.printStackTrace ();} M%@=BT
catch(Exception e){e.printStackTrace ();} ]YqeI*BX
[bZASeh
:^*9Eb
Utility.log(nFileLength); M-+pYv#&P
~vv\A5O[|
QJKVNOo
return nFileLength; mvrg!/0w
} -Ka0B={Z
dd|/I1
T*irCe
//保存下载信息（文件指针位置） w$)E#|i
private void write_nPos() 6z>Zm1h
{ ?~fuMy B
try{ hY^-kdQ>M
output = new DataOutputStream(new FileOutputStream(tmpFile)); {nyVC%@Y
output.writeInt(nStartPos.length); E])X$:P?
for(int i=0;i<nStartPos.length;i++) dX>l"))yR
{ tW7*(D
// output.writeLong(nPos); {nl4(2$
output.writeLong(fileSplitterFetch.nStartPos); =`y.L5
output.writeLong(fileSplitterFetch.nEndPos); RBM(>lU:
} G>H',iOI
output.close(); Kl)PF),
} "J(7fL$!
catch(IOException e){e.printStackTrace ();} T.R(
catch(Exception e){e.printStackTrace ();} hp6%zUR
} wU=@,K
2 bQC2
{S;/+X,
//读取保存的下载信息（文件指针位置） }iF"&b0n"
private void read_nPos() \/ 8 V|E
{ Gkq<?q({t
try{ d}e/f)(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |e#ea~/b
int nCount = input.readInt(); a}]zwV&
nStartPos = new long[nCount]; \JX.)&> -
nEndPos = new long[nCount]; I_/kJ#7vj
for(int i=0;i<nStartPos.length;i++) #6 yi
{ {2,OK=XM|
nStartPos = input.readLong(); a|\ZC\(xI
nEndPos = input.readLong(); p"XQJUuD
} .Lc<1s
input.close(); i'}Z>g5D
} ?a]uyw,
catch(IOException e){e.printStackTrace ();} !`-/E']/
catch(Exception e){e.printStackTrace ();} MX.=k>
} !Qd4Y=
lY_&P.B
V$7SVq
private void processErrorCode(int nErrorCode) TtaVvaz~>
{ {V)Z!D
System.err.println("Error Code : " + nErrorCode); ctg[C$<q|
} pdQ6/vh
.sk$@Q
5I(gP
//停止文件下载 TXlxnB
public void siteStop() Uhz<B #tj
{ P{!r<N
bStop = true; 7k>sE
for(int i=0;i<nStartPos.length;i++) ou[_ y
fileSplitterFetch.splitterStop(); <r%QaQRbm
b-x,`s
+R_w- NI
} ^KsiTVY
} fy`e)?46
//负责部分文件的抓取 ,.ln
**FileSplitterFetch.java (|PxR#{l<
*/ qq+fUfB2:
package NetFox; 3B<$6
#sq$i
_=.f+1W
import java.io.*; 3Hli^9&OX_
import java.net.*; >|[74#}7
MOIH%lpe
`<C/-Au
public class FileSplitterFetch extends Thread { Y M_\ ZK:
i-b++R/WN
7xOrG],E
String sURL; //File URL 'RlPj0Cg
long nStartPos; //File Snippet Start Position JKkR963 O
long nEndPos; //File Snippet End Position P*#H]Pv
int nThreadID; //Thread's ID yBPaGZ{f
boolean bDownOver = false; //Downing is over `.FvuwP
boolean bStop = false; //Stop identical P"<HxT?
FileAccessI fileAccessI = null; //File Access interface d2x|PpmH
&.Jp,Xt)
~8-Z=-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [kyF|3k~
{ CjtXU=}A
this.sURL = sURL; mGXjSWsd
this.nStartPos = nStart; ^]$x/1I;
this.nEndPos = nEnd; kphv)a4z=
nThreadID = id; ( *(#;|m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^fLePsmd
} \wxS~T<&L
]Xur/C2A
pv=g)
public void run() ;^Vsd\ac0
{ OgiElA.
while(nStartPos < nEndPos && !bStop) "b!EtlT9
{ !`k{Ga
(o1*7_]e
>C`b4xQ
try{ +oZq~2?*S6
URL url = new URL(sURL); K.Tfu"6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .O{2]e$
httpConnection.setRequestProperty("User-Agent","NetFox"); >5&'_
String sProperty = "bytes="+nStartPos+"-"; =8r%zLDw
httpConnection.setRequestProperty("RANGE",sProperty); 3hOiHO ;
Utility.log(sProperty); DHO6&8S
jB*%nB*x
ZkW,
InputStream input = httpConnection.getInputStream(); ?*~W
//logResponseHead(httpConnection); bUf2uWy7
[<Wo7G1s
x.CNDG
byte[] b = new byte[1024]; /HsJyp+t
int nRead; b8QA>]6A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %pNK ?M+
{ -v4kW0G
nStartPos += fileAccessI.write(b,0,nRead); Lt+ Cm$3
//if(nThreadID == 1) ngprTMO$&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,%#FK|
} Ji_3*(
3[E3]]OVa
bu[v[U4
Utility.log("Thread " + nThreadID + " is over!"); kzG mDi
bDownOver = true; + RX{
//nPos = fileAccessI.write (b,0,nRead); TKpka]nJ
} njveZav
catch(Exception e){e.printStackTrace ();} F$UvYy4O d
} ,YYyFMC7S
} #Mt'y8|}$
ugEh}3
X !g"D6'
//打印回应的头信息 %vvA'WG
public void logResponseHead(HttpURLConnection con) I @TR|
{ c rPEr
for(int i=1;;i++) ~F^(O{EG
{ a$p?r3y
String header=con.getHeaderFieldKey(i); wK+%[i&,
if(header!=null) b-8{bP]n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _ji"##K
Utility.log(header+" : "+con.getHeaderField(header)); V,<3uQD9a
else #1i&!et&/
break; WG8}}`F|
} LfEeFF=#n
} W3s>+yU
V?Y;.n&y
m$ZPQ0X
public void splitterStop() @UCGsw
{ =7@N'xX
bStop = true; $<.\,wW*'w
} bI 3o|
79|=y7i#
:c@v_J6C&
} \jDD=ew
kw&,<V77~
=X[]0.I%
/* B#Cb`b"
**FileAccess.java o(GXv3L
*//文件访问(定位，写) p]/HZS.-b
package NetFox; YIv!\`^ \
import java.io.*; ezn%*X y,
<R)%K);
8"L#5MO t
public class FileAccessI implements Serializable{ 4}@J]_]Z
DD`Bl1)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &~of]A
RandomAccessFile oSavedFile; O4w6\y3U
long nPos; ?ACflU_k
+eSNwR=
hh/C{ l
public FileAccessI() throws IOException kH'LG!O
{ I8;xuutc
this("",0); QOA7#H-m9
} 36mp+}R#
!"~x.LX\
(jbHV.]P9
public FileAccessI(String sName,long nPos) throws IOException oc+TsVt
{ v?e@`;- <
oSavedFile = new RandomAccessFile(sName,"rw"); F?#^wm5TZ
this.nPos = nPos; 6-8,qk
oSavedFile.seek(nPos); K.s\xA5`_
} |[apLQ6
'B dZN
&[u%ZL
public synchronized int write(byte[] b,int nStart,int nLen) cPD&xVwq>
{ IE7%u92
int n = -1; b&[bfM<
try{ \ng!qN
oSavedFile.write(b,nStart,nLen); `}t<5_
n = nLen; :.8@ xVH
} VfWU-lJ
catch(IOException e) d:C|laZHn
{ 1t&LNIc|^
e.printStackTrace (); v_M-:e3`
} xQLVFgd
1iNq|~
Vwxb6,}Z
return n; E,u/^V9x
} H_w&_h&
/-%0y2"7
g{|F<2rd[m
} \4$V;C/n,
+i"^"/2f{
.g/PWEr\I
/* SI_u0j4%*
**SiteInfoBean.java uG-t)pej
*/ vmEbk/Vy
package NetFox; {A<pb{<u
F|mppY'<J
Y:f"Zx
public class SiteInfoBean { u^2)oL
kAc8[Hn
[;6,lI}
private String sSiteURL; //Site's URL C_CUk d[
private String sFilePath; //Saved File's Path (*qMs)~]B
private String sFileName; //Saved File's Name fcaUj9qN
private int nSplitter; //Count of Splited Downloading File *CtWDUxSdW
7]\_7L|>]
KHnq%#
public SiteInfoBean() tqok.h
{//nSplitter的缺省值为5 73C7g< Mx
//default value of nSplitter is 5 Fsdp"X.
this("","","",5); ~9Xs=S!
} +95: O 8
V46=48K.
=:neGqd\_E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3[_zz;Y*d
{ HNXMM
sSiteURL= sURL; 2TQyQ%
sFilePath = sPath; b*5Yy/U
sFileName = sName; Gl am(V1
this.nSplitter = nSpiltter; MBp,!_Q6
~F)[H'$A
{Q?\%4>2
} XC*!=h*
_8QHx;}
U5[,UrC
public String getSSiteURL() %Z.!T
{ yj<j>JtN
return sSiteURL; mFk6a{+YX
} "UM*(&
YRU1^=v
@m`1Vq?O
public void setSSiteURL(String value) y)//u:l
{ 77zfRSb+
sSiteURL = value; 0:C^-zrx
} ,ma4bqRMc
!tuN_
rlRRGJ\l
public String getSFilePath() au+6ookT
{ a ]b%v9
return sFilePath; "gIjU~'A
} $bo,m2)
\I-bZ|^
n0 q$/Y.
public void setSFilePath(String value) Jxo#sV-
{ U"T>L
sFilePath = value; s[dq-pc"
} +.3,(l
a_V.mu6h6p
K?J?]VCw
public String getSFileName() 9coN >y
{ }LA7ku
return sFileName; +$CO
} #Y_v0.N
E9N.b.Q)
*B*dWMh
public void setSFileName(String value) 8+|7*Ud
{ <&CzM"\Em
sFileName = value; &sA@!
} =@\Li)Y
nqv#?>Z^OT
e0e3b]
public int getNSplitter() CqAv^n7 }
{ O!3`^_.
return nSplitter; {Gi:W/jJ
} 9zKbzT]
=5kTzH.
IpYw<2'
public void setNSplitter(int nCount) z~0f[As.
{ 5^0K5R6GQf
nSplitter = nCount; #J w\pOn
} #Zq[.9!q{
} S(NUuu}S
VT:m!<^
b&g`AnYT
/* u.!<)VIJx
**Utility.java 8]2j*e0xV
*/ ^`f( Pg!
package NetFox; wK*b2r}0/
|]=s
,\CG}-v@CN
public class Utility { ( L ]C
}'c@E0"
z@tIC^s
public Utility() y&(R1Y75
{ ,/1[(^e
iosL&*'8
7a#zr_r
} B,NHy C1i
~'u %66
//线程睡眠 TM*<hC
public static void sleep(int nSecond) k1sR^&{l
{ j"J[dlm2M
try{ ]/TqPOi:
Thread.sleep(nSecond); $hgsWa
} y0b FzR9
catch(Exception e) Fq`wx
{ rvwfQ'14
e.printStackTrace (); .4cOMiG
} hcJny
} RI0+9YJ
-)o0P\cTEt
//日志 bqI| wGCA"
public static void log(String sMsg) ?YA5g' l
{ PTf.(B"z
System.err.println(sMsg); kFZjMchm A
} zrazFI0G
Z:kX9vw.
se^(1R k
public static void log(int sMsg) *p>1s!i
{ m L,El2
System.err.println(sMsg); :978D0}{p
} ANWUo}j
} "PtOe[Xk
YThFskRoO
@K}8zMmW#
/* h"849c;C.
**TestMethod.java Yv7`5b{N.
*/ +`$[h2Z=:
package NetFox; h8-'I=~
-_xC,dwK
;d{lvKk
public class TestMethod { c:f++||
=F>nqklc
GTBT0$9g.
public TestMethod() x}*Y =Xh
{ ///xx/weblogic60b2_win.exe vo3[)BDbT
try{ -7\6j#;l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;DN:AgXP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OK1f Y`$z
SiteFileFetch fileFetch = new SiteFileFetch(bean); n?z^"vv$i
fileFetch.start(); AfOq?V
} O:86*
catch(Exception e){e.printStackTrace ();} U<Z\jT[
HZ.Jc"+M
sXmo.{Ayb
} y|0I3n]e
D-!#TN`Y
BH$+{rZ8t
public static void main(String[] args) 3V2w1CERE
{ j"Vb8}
new TestMethod(); 9CW8l0
} YTo^Q&
} ;rJ
点击下载更多相关资料