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)); fmc\Li
} 5s`r&2 w
for(int i=0;i<nEndPos.length-1;i++) )7o?}"I
{ h,]VWG
nEndPos = nStartPos[i+1]; [)~1Lu
} v}d)uPl};
nEndPos[nEndPos.length-1] = nFileLength; G'PZ=+!XO/
} 6yMZ2%
} _*Z3,*~"X
?# _{h
N~l*//Ep
//启动子线程 ^+CHp(X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~!8j,Bqs+z
for(int i=0;i<nStartPos.length;i++) QKlsBq
{ f86Z #%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m_@XoS yxI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0< vJ*z|_
nStartPos,nEndPos,i); !Hl]&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l!&ik9m
fileSplitterFetch.start(); 9!W$S[ABRB
} xy"'8uRi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $/;K<*O$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yv@n$W`:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WulyMcJ
nEndPos = " + nFileLength); bE'{zU}o
// fileSplitterFetch[nPos.length-1].start(); 0gaHYqkA>}
OWT%XUW=
q`IY;"~
//等待子线程结束 $[,4Ib_|
//int count = 0; Sp:w _;{#
//是否结束while循环 Rb&9!z
boolean breakWhile = false; <r t$~}
+qC[X~\
]S[?tn
while(!bStop) -D'XxOI
{ Bdb}4X rL
write_nPos(); 'Kbrz
Utility.sleep(500); wL="p) TO.
breakWhile = true; n-l_PhPQ`
CW?Z\
ftR& 5!Wm
for(int i=0;i<nStartPos.length;i++) 83t/\x,Q
{ cGgfCF^`
if(!fileSplitterFetch.bDownOver) ?Y,^Moc:
{ 'xxM0Kn`
breakWhile = false; Z_m<x!
break; *URT-+'
} tzIP4CR~F&
} "V26\
if(breakWhile) p'2IlQ\
break; 4^bt~{}
>$L7J=Em
igk<]AwxS
//count++; PE4 L7
//if(count>4) R)Arr77
// siteStop(); #O\as~-
} $Vq5U9-
xn503,5G*7
5}ftiy[Yc
System.err.println("文件下载结束！"); :ZIa
} pa+'0Y]71
catch(Exception e){e.printStackTrace ();} -kMw[Y
} _Tor9Tj
nM2<u[{gF
Q'Osw"
//获得文件长度 (b<0=U
public long getFileSize() 7)r]h?
{ ~a`[p\
int nFileLength = -1; dVEs^ZtI
try{ eDZ8F^0
URL url = new URL(siteInfoBean.getSSiteURL()); \?T9v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C:5-h(#
httpConnection.setRequestProperty("User-Agent","NetFox"); Fw\Z[nh
ckA\{v
0ck3II
int responseCode=httpConnection.getResponseCode(); wb?k
if(responseCode>=400) ge GhM>G
{ [=q/f2_1.
processErrorCode(responseCode); =N\; ?eF(
return -2; //-2 represent access is error {Fw"y %a^
} Si?s69
/#M1J:SV
CMW4Zqau*
String sHeader; U\?D;ABQ%
49&i];:%7%
S1U0sP@o
for(int i=1;;i++) (!5Ta7X
{ o&E8<e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eb\SpdM6
//Utility.log(in.readLine()); S7f.^8
sHeader=httpConnection.getHeaderFieldKey(i); T3{~f
if(sHeader!=null) /h+ W L
{ dnoF)(d&Cm
if(sHeader.equals("Content-Length")) K!&W}_@l
{ z0<E3t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nZ(]WPIN"
break; 3P2{M}WIl
} `K.C>68
} x'x5tg
else xj>P5\mW#
break; fe/;U=te
} .b3h?R*&
} JVX)>2&$
catch(IOException e){e.printStackTrace ();} h{^v756L
catch(Exception e){e.printStackTrace ();} )4=86>XJT
OA&'T*)-A6
E.Xp\Dm71
Utility.log(nFileLength); M0fN[!*z
$kTm"I
x:MwM?
return nFileLength; s"=TM$Vb
} 8c)GUx
>^jBE''
$45|^.b
//保存下载信息（文件指针位置） l'EO@D/M
private void write_nPos() ]i.N'O<p
{ QX<n^W
try{ A,<5W }
output = new DataOutputStream(new FileOutputStream(tmpFile)); {wz)^A sy
output.writeInt(nStartPos.length); ,^?g\&f(
for(int i=0;i<nStartPos.length;i++) qhxMO[f
{ hi!A9T3%}M
// output.writeLong(nPos); ;^xM" {G8
output.writeLong(fileSplitterFetch.nStartPos); $C7a#?YF,
output.writeLong(fileSplitterFetch.nEndPos); +Pl)E5W!=`
} :6nD"5(
output.close(); qhGz2<}_j
} _HHvL=
catch(IOException e){e.printStackTrace ();} #kM|!U=
catch(Exception e){e.printStackTrace ();} 6T$=(I <4
} ,yltt+e
AyO%,6p[
i#*[, P~
//读取保存的下载信息（文件指针位置） uAA2G\3
private void read_nPos() b_~XTWP$l
{ `&D#P%
try{ RBrb7D{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =Q(J!f
int nCount = input.readInt(); !~vK[G(R
nStartPos = new long[nCount]; kFp^?+WI%H
nEndPos = new long[nCount]; c36p+6rJk=
for(int i=0;i<nStartPos.length;i++) 'z"vk
{ /Yy)=~t{
nStartPos = input.readLong(); p [C 9g
nEndPos = input.readLong(); 0 MK}
} 5VTVx1P[8
input.close(); ~6t!)QATnp
} $vu*# .w
catch(IOException e){e.printStackTrace ();} -n9&W
catch(Exception e){e.printStackTrace ();} ^\ x'4!W
} fY&TI}Y
#!F>cez
xA Ez1
private void processErrorCode(int nErrorCode) wPM>-F
{ IQO|)53)
System.err.println("Error Code : " + nErrorCode); >g{&Qx`&
} P_A@`eU0
wH o}wp
1;(h0j
//停止文件下载 gvR]"h
public void siteStop() 6NX#=A
{ Gf"TI:xa
bStop = true; i"a3POV>
for(int i=0;i<nStartPos.length;i++) nm1dd{U6^
fileSplitterFetch.splitterStop(); [L+*pW+$\.
k4V3.i!E
?-)!dl%N
} k 3m_L-
} [=(8yUV'G
//负责部分文件的抓取 (Y)2[j
**FileSplitterFetch.java OWewV@VXR
*/ lk 1\|Q I
package NetFox; 53:~a
<8b1OdA
(U&
import java.io.*; -SM_JR3<
import java.net.*; $$m0mK
P5?VrZy
> mO*.'Gm
public class FileSplitterFetch extends Thread { pRun5 )7
Qa_V
g:fvg!_v
String sURL; //File URL R#hy2kA
long nStartPos; //File Snippet Start Position PN93.G(W
long nEndPos; //File Snippet End Position vQ*[tp#qU
int nThreadID; //Thread's ID 0fewMS*
boolean bDownOver = false; //Downing is over FJZ'P;3
boolean bStop = false; //Stop identical cK1^jH<|
FileAccessI fileAccessI = null; //File Access interface ~".@mubt1$
I.3~ctzu
V,rc&97
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -E?:W`!
{ o^~ZXF}
this.sURL = sURL; @[J6JT*E
this.nStartPos = nStart; *,Bm:F<m
this.nEndPos = nEnd; T$lV+[7
nThreadID = id; .+1I>L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #sc!H4
} !*:g??[T
62HA[cr&)
06]3+s{{
public void run() E'aOHSAg
{ X\Bl? F
while(nStartPos < nEndPos && !bStop) .hmeP MK
{ Ts !g=F
"6'",
f8lyH'z0 @
try{ $Lj]NtO
URL url = new URL(sURL); <u\Hy0g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b5|*p(7[
httpConnection.setRequestProperty("User-Agent","NetFox"); #1haq[Uv7
String sProperty = "bytes="+nStartPos+"-"; !-}Q{<2@W
httpConnection.setRequestProperty("RANGE",sProperty); I9Ohz!RQ
Utility.log(sProperty); IVh5SS
/GGyM]k3
UH>~Y N
InputStream input = httpConnection.getInputStream(); 7_ix&oVI
//logResponseHead(httpConnection); z)C}}NH*!@
#4m5I="
i6V$mhL
byte[] b = new byte[1024]; 6#U~>r/
int nRead; ]!AS%D`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FXBmatBck
{ "v:k5a(
nStartPos += fileAccessI.write(b,0,nRead); (O J/u)W^
//if(nThreadID == 1) O6Py
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5&s6(?,Eu
} 9Do75S{(
$^fF}y6N
1TQ?Fxj
Utility.log("Thread " + nThreadID + " is over!"); Xq$-&~
bDownOver = true; @!")shc
//nPos = fileAccessI.write (b,0,nRead); 4JK6<Pk
} nCi ]6;Y
catch(Exception e){e.printStackTrace ();} W5Z-s.o
} :<P4=P P
} GPHb-
+ -Rf@
6HCg<_j]
//打印回应的头信息 f)_<Ih\/7_
public void logResponseHead(HttpURLConnection con) LKvX~68
{ @LI;q
for(int i=1;;i++) m[=SCH-;
{ W\>O$IX^e
String header=con.getHeaderFieldKey(i); 5Lc@=,/0
if(header!=null) H"/JR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7310'wc
Utility.log(header+" : "+con.getHeaderField(header)); E9\"@wu[d
else GbO j% a
break; neu+h6#H
} A>gZl)c
} S Q:H2vvD
:0y-n.-{
>!1]G"U
public void splitterStop() s;bGg
{ AHs%?5YTY;
bStop = true; ,mm97I
} -E\G3/*51
y?UJ<QAi
TI3xt-/
} 3q4Zwv0z20
0 8L;u7u
oA5Qk3b:
/* a&G{3#l
**FileAccess.java H'3 pHb
*//文件访问(定位，写) S=P}Jpq?Y;
package NetFox; z+.G>0M
import java.io.*; VL*5
\9,lMK[b
I7Kgi3
public class FileAccessI implements Serializable{ TFb7P/g
Z]Xa:[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4e>f}u5
RandomAccessFile oSavedFile; Gs"lmX-{$j
long nPos; |rJN
o%+w:u.
gtH^'vFZ
public FileAccessI() throws IOException U $#^ e
{ 2#$7!`6K
this("",0); *1v3x:pQ'
} b(N+_= n
agfDx^,
{G=>WAXo
public FileAccessI(String sName,long nPos) throws IOException N_:!uR
{ @{qcu\sZ
oSavedFile = new RandomAccessFile(sName,"rw"); H%n/;DW
this.nPos = nPos; j6^.Q/{^
oSavedFile.seek(nPos); ^kK")+K
} w@2NXcmw
w +UBXW
DA=LR
public synchronized int write(byte[] b,int nStart,int nLen) W\B@0Iso
{ 1sza\pR<
int n = -1; Tg O]q4
try{ H8"RdKwg?
oSavedFile.write(b,nStart,nLen); ^4WZ%J#g
n = nLen; A?HDY_u
} ksU& q%1
catch(IOException e) 9u=]D> kb
{ JT}"CuC
e.printStackTrace (); J",Cwk\
} >1Iw!SO+
[i~@X2:Al
RoHX0
return n; qK;J:GT>
} GKg #nXS
JqLPJUr
=S54p(>
} 7mnO60Z8N
w`boQ_Ir
Y_$!XIJ4
/* lz0dt<8eP
**SiteInfoBean.java 8B6(SQp%
*/ n=rmf*,?
package NetFox; l{rHXST|
g NE"z
uUaDesz~=
public class SiteInfoBean { ax _v+v %
dn~k_J=p
W"/,<xHuh
private String sSiteURL; //Site's URL # .&t'"u
private String sFilePath; //Saved File's Path 9_*3xu<7i
private String sFileName; //Saved File's Name ~]%re9jGW
private int nSplitter; //Count of Splited Downloading File rr1,Ijh{D
Q.4+"JoG
{3os9r,
public SiteInfoBean() $!'Vn)Z7
{//nSplitter的缺省值为5 G|&$/]~
//default value of nSplitter is 5 %j0c|u
this("","","",5); C.=%8|Zy
} }rVLWt
C]ho7qC
qzY:>>d'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3 P\4K
{ 3KD:JKn^
sSiteURL= sURL; sFfargl
sFilePath = sPath; iU{\a,
sFileName = sName; >PWDo
this.nSplitter = nSpiltter; :`yW^b
`aMnTF5:
9@h-q(-
} V?MaI.gj
+A 6kw%"
"5,Cy3
public String getSSiteURL() , Z1 &MuV
{ o 8^!wGY
return sSiteURL; 4.%/u@rAi
} z2.OR,R}]
ODCN~7-@
H-& ktQWK3
public void setSSiteURL(String value) xjDaA U,
{ kU)E-h
sSiteURL = value; v~^*L iP+
} *~#`LO
{R~L7uR@O
M1DV9~S
public String getSFilePath() 4GJx1O0Ol
{ )1 0aDTlr
return sFilePath; wXeJjE%j:3
} '}Jq(ah(
;M#D*<ucI:
noWwX
public void setSFilePath(String value) ewYk>
{ KmF+3g~#s
sFilePath = value; k V'0rb
} z\J#d 1e
&C/,~pJ1S
o2y #Yk
public String getSFileName() Xs4G#QsAJ
{ 2c9]Ja3:6
return sFileName; q={3fm
} x5yZ+`Gc
yle~hL
a^L'-(
public void setSFileName(String value) bsWDjV~
{ n QOLR?%
sFileName = value; M)nf(jw#G
} IrP6Rxh
b\"2O4K,)
F>q%~
public int getNSplitter() B&lF! ]
{ }PzYt~Z`@
return nSplitter; =H^^AG\}
} mhnK{M @56
"OKsl2e
'6>nXp?)r
public void setNSplitter(int nCount) 4d]T`
{ ])T_&%
nSplitter = nCount; t7$2/C
} 0K^G>)l
} m}-~VYDj
/ ='/R7~
z:tu_5w!,
/* k@C]~1
**Utility.java gl6*bB=
*/ Y4/ !b
package NetFox; ?37Kc,o
8!dA1]2;
"IsDL^)A9
public class Utility { NB/ wJ3 F
T$xY]hqr
ki_Py5
public Utility() 852Bh'u_
{ Qte'f+
`ZAGseDd~
Y'i_EX|
} @7B!(Q
.zyi'Kj
//线程睡眠 $zV[-d
public static void sleep(int nSecond) &AlX).
{ a@WSIcX*W
try{ 8h7z
Thread.sleep(nSecond); 7b[vZNi_
} }q@Jh*
catch(Exception e) ,`< [ej
{ K1Wiiw
e.printStackTrace (); ijWn,bj
} 1QH5<)Oa
} {wp"zaa
owc#RW9 7
//日志 > jvi7
public static void log(String sMsg) 3YPoObY
{ i;B)@op.#
System.err.println(sMsg); s5ddGiZnBT
} Cy##+u,C
$nbZ+~49
:<Y, f(c
public static void log(int sMsg) w873: =
{ 9y"*H2$#
System.err.println(sMsg); 7w{>bYP
} PYz^9Ud 6g
} ra k@oW]
h"G#} C]
u($y<Q)=
/* K%A:W
**TestMethod.java hK&/A+*
*/ <$'OSN`!
package NetFox; GoNX\^A
qTL]
miZ&9m
public class TestMethod { aE(j_`L78
jDO[u!J6.%
H-o>|C
public TestMethod() bR!*z
{ ///xx/weblogic60b2_win.exe <M|kOi
try{ ca1A9fvo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H)5v X+9D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O=PyXOf
SiteFileFetch fileFetch = new SiteFileFetch(bean); PNn{Rt
fileFetch.start(); BK8)'9/
} P*6B+8h"5g
catch(Exception e){e.printStackTrace ();} Q}M% \v
r0)X]l7
Ojf.D6nY
} ^?H3:CS
|%R}!O<.c
EnGVp<6R
public static void main(String[] args) C&m[/PJ~l
{ EI*B(
new TestMethod(); Rb~NX
} Vn-y<*np
} ;V~[kF=t0
点击下载更多相关资料