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)); Vewzo1G2
} R2^iSl%pj
for(int i=0;i<nEndPos.length-1;i++) pCt}66k}
{ 981!2*
nEndPos = nStartPos[i+1]; tV`&-H
} hZuYdV{'h
nEndPos[nEndPos.length-1] = nFileLength; f=ib9WbR#
} 5u,sx664
} xH$%5@~
dF,DiRD
< l[`"0
//启动子线程 FmA-OqEpA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k,]{NO
for(int i=0;i<nStartPos.length;i++) v MWC(m
{ ?UK:sF|(O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MZ^Ch
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P1QB`&8F
nStartPos,nEndPos,i); Qa?QbHc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rqC1
fileSplitterFetch.start(); M,{<TpCx
} N7B}O*;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s}!"a8hU`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DZAH"sb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WFdem/\kX
nEndPos = " + nFileLength); 2V<# Y
// fileSplitterFetch[nPos.length-1].start(); h>Rpb#]
!L$oAqW
CU !.!cZ{
//等待子线程结束 ~$ WQ"~z
//int count = 0; 8)`5P\
//是否结束while循环 _^3@PM>
boolean breakWhile = false; ]eL~L_[G\
^ N_`^m
h=mv9=x
while(!bStop) @f'AWeJ2
{ OAyE/Q|
write_nPos(); JgZdS-~
Utility.sleep(500); Ua!Odju*w
breakWhile = true; Ot"(uW4$[
"lb\c
,dq`EsHg`M
for(int i=0;i<nStartPos.length;i++) LQ|<3]
{ 7dx4~dF
if(!fileSplitterFetch.bDownOver) '.xkn{c
{ 1r&AB!Z #
breakWhile = false; s-o~@(r6
break; )%1&/uN)
} pe|\'<>i
} CTh1;U20
if(breakWhile) t"FRLC
break; 3pzOt&T|w
F.&*D~f
,7/\&X<`B
//count++; 7{8)ykBU^
//if(count>4) ]dQZ8yVK
// siteStop(); SwQOFE/Dv~
} f61]`@Bk
$Jt8d|UP
(rMTW+,
System.err.println("文件下载结束！"); 96k(XLR
} iNMLYYq]l
catch(Exception e){e.printStackTrace ();} VdYOm
} g8B&u u #
FxMMxY,*%
` C/fF_YA
//获得文件长度 d u_O}x
public long getFileSize() _LLW{^V
{ ',<{X(#(
int nFileLength = -1; VN1#8{
try{ E%KC'TN^D
URL url = new URL(siteInfoBean.getSSiteURL()); UX+?0K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6!i( \Q*
httpConnection.setRequestProperty("User-Agent","NetFox"); |2tSUOZ
&FT5w T
zV9 =
int responseCode=httpConnection.getResponseCode(); pvK \fSr
if(responseCode>=400) V/+H_=|
{ &n,xGIG
processErrorCode(responseCode); 9G=A)j
return -2; //-2 represent access is error eU<]h>2
} fLf#2EA
KI^q 5D ?
jKe$&.q@
String sHeader; R A-^!4tX
#h}IUR
>c~9wv
for(int i=1;;i++) $u(M 4(}
{ F=P+;%.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :K a^
//Utility.log(in.readLine()); W\ZV0T;<]
sHeader=httpConnection.getHeaderFieldKey(i); Lcm~QF7cd
if(sHeader!=null) 7cJO)cm0'
{ m7bn%j-{$f
if(sHeader.equals("Content-Length")) loAfFK>g
{ A@fshWrl%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?}!gLp
break; D~t"9Z\
} @p?b"?QaB
} 1VPfa
else S:"z<O
break; tOp:e KN
} >*ha#PE
} "m<eHz]D
catch(IOException e){e.printStackTrace ();} Xv<;[vq}F
catch(Exception e){e.printStackTrace ();} DT1i2!
X8NO;w@z#
UGezo3}
Utility.log(nFileLength); -O5(%
/I`!iK
3z{5c
return nFileLength; n8y,{|
} P*nT\B
NC[GtAPD3
9cx!N,R t
//保存下载信息（文件指针位置） )e <! =S
private void write_nPos() b*F :l#
{ dcc%G7w
try{ C$Hl`>?$
output = new DataOutputStream(new FileOutputStream(tmpFile)); +p%5/smfs
output.writeInt(nStartPos.length); (Mire%$h
for(int i=0;i<nStartPos.length;i++) IJb1) ZuR
{ +X|m>9
// output.writeLong(nPos); 6=`m
output.writeLong(fileSplitterFetch.nStartPos); ]R3pBC"Jv
output.writeLong(fileSplitterFetch.nEndPos); el*pYI
} }G:uzud10
output.close(); M}KM]<
} \w@_(4")Qb
catch(IOException e){e.printStackTrace ();} \Z7([Gh
catch(Exception e){e.printStackTrace ();} q4#f *]
} b&V]|Z(
,oi`BOh
\i;~~;D
//读取保存的下载信息（文件指针位置） lXL7q?,9
private void read_nPos() TF iM[
{ {dr&46$p
try{ <:yq~?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .8uwg@yD
int nCount = input.readInt(); 9'*ZEl^?D
nStartPos = new long[nCount]; l!2Z`D_MD
nEndPos = new long[nCount]; F~rYjAFTi
for(int i=0;i<nStartPos.length;i++) xvz5\s|b
{ aSj1P/A
nStartPos = input.readLong(); D A)0Y_
nEndPos = input.readLong(); Hk~ gcG
} CTrs\G
input.close(); K7R])*B.~
} H6 f; BS
catch(IOException e){e.printStackTrace ();} _I}L$
catch(Exception e){e.printStackTrace ();} m-KK {{
} :R*^Izs=
{ `|YX_HS
&)f++(i
private void processErrorCode(int nErrorCode) {'Qk>G s
{ P+%)0*W
System.err.println("Error Code : " + nErrorCode); mP .&fS
} { )GEgC
eYX_V6c
JE:n`l/p
//停止文件下载 yLIj4bf
public void siteStop() T_9ZI|Jx
{ f;XsShxr
bStop = true; ;gu>;_
for(int i=0;i<nStartPos.length;i++) 0}7Rm>
fileSplitterFetch.splitterStop(); ci NTYow
xS-nO_t 'E
GTIfrqT
} ~aR='\<
} ].T;x|
//负责部分文件的抓取 yc4f\0B/
**FileSplitterFetch.java h/bYtE
*/ Cy> +j{%!
package NetFox; >,]e[/p
VGUDUM.8
@DC2ci >
import java.io.*; e%0#"6}
import java.net.*; Iybpk?,M+
1~u\]Zi=D
-V_S4|>
public class FileSplitterFetch extends Thread { W9m[>-Ew
N4(VRA
*>*/|
String sURL; //File URL 1Kf t?g
long nStartPos; //File Snippet Start Position Y},GZ^zqy
long nEndPos; //File Snippet End Position bme#G{[)Y
int nThreadID; //Thread's ID QM=436fq
boolean bDownOver = false; //Downing is over *_rGBW
boolean bStop = false; //Stop identical R.'Gg
FileAccessI fileAccessI = null; //File Access interface %=O!K>^vt<
0bL=l0N$W
uqeWdj*Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]BD5+>;
{ E_uH'E
this.sURL = sURL; 4xn^`xf9
this.nStartPos = nStart; aNU%OeQA
this.nEndPos = nEnd; A8/4:>Is
nThreadID = id; F(fr,m3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tka="eyIj3
} Ijro;rsEKM
zVLi
kV9NFo22
public void run() < io8 b|A
{ x&b-Na3Xi
while(nStartPos < nEndPos && !bStop) OWfj<#}t+
{ |i}g7
19`0)pzZ*P
k6XmBBIj-
try{ (\Zo"x;(
URL url = new URL(sURL); *n?:)(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); boB{Y7gO4
httpConnection.setRequestProperty("User-Agent","NetFox"); leJd){
String sProperty = "bytes="+nStartPos+"-"; $gK>R5^G>
httpConnection.setRequestProperty("RANGE",sProperty); 'E8Qi'g
Utility.log(sProperty); bdhgHjz
SP1oBR"3
v!C+W$,T
InputStream input = httpConnection.getInputStream(); hd%F7D5
//logResponseHead(httpConnection); 6RodnQ
^TK)_wx
DTVnQC
byte[] b = new byte[1024]; ~,7R*71
int nRead; hIr^"kVK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <u/({SZ&
{ bvTkSEN
nStartPos += fileAccessI.write(b,0,nRead); M)Q+_c2*
//if(nThreadID == 1) #TF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YHAg4eb8
} \ .s".aA
?C\9lLX
GdY^}TJrh
Utility.log("Thread " + nThreadID + " is over!"); nK=V`
bDownOver = true; &>t1A5
//nPos = fileAccessI.write (b,0,nRead); ~h+3WuOv
} n8,/olqwW
catch(Exception e){e.printStackTrace ();} &p/k VM
} .1}(Bywm5
} &|*|
{4*%\?c,n
=Ybu_>
//打印回应的头信息 \ziF(xTvqG
public void logResponseHead(HttpURLConnection con) m!(K
{ CB)#; |aDB
for(int i=1;;i++) 4ebGAg?_
{ c?S402M}
String header=con.getHeaderFieldKey(i); sBL^NDqa2
if(header!=null) aH~"hB^e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Z&R'`kg
Utility.log(header+" : "+con.getHeaderField(header)); |JQ05nb
else %Kp}Wo6
break; T94$}- 5/)
} THVF@@q
} Gx)D~7lz
SYx)!n6U
0g\&3EvD
public void splitterStop() =c'LG
{ 'Ud5;?{
bStop = true; ]W,g>91m
} ~gD]JiiA
!5-[kG&
k=[Ro
} !$HWUxM;p
MiRB*eA
KNhH4K2iP8
/* EzaOg|
**FileAccess.java RZjR d
*//文件访问(定位，写) Xs/hqIXB
package NetFox; sYzG_*)
import java.io.*; oCS NA.z
.wywO|
{JJ`|*H$_
public class FileAccessI implements Serializable{ =k z;CS+
Oc>-jhx?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y:L|]p}huE
RandomAccessFile oSavedFile; RWE%?`
long nPos; Yu=^`I
%oo&M;
]F~5l?4u#
public FileAccessI() throws IOException EMo6$(
{ -h}J%UV
this("",0); 6dh PqL
} FYJB.lAT
tj0vB]c
lMP7o&
public FileAccessI(String sName,long nPos) throws IOException HFazqQ[
{ $W2AiE[Wm
oSavedFile = new RandomAccessFile(sName,"rw"); C+Z"0\{o
this.nPos = nPos; gM8eO-d
oSavedFile.seek(nPos); VF-d^AGt
} 1NTe@r!y
^iTA40K
M\%{!Wzo8
public synchronized int write(byte[] b,int nStart,int nLen) R[(,wY_1
{ ) E\pQ5&
int n = -1; :A$6Y*s\
try{ B.|vmq,u
oSavedFile.write(b,nStart,nLen); qhtc?A/0}
n = nLen; 1L0ku@%t9Y
} MG6Tk(3S
catch(IOException e) hug12Cu
{ gOkO8P6P8
e.printStackTrace (); V6L_aee}CK
} 5^xt/vYa)
!\m.&lk'^
h\5 7t@A
return n; UaBR;v-.B3
} ;9~z_orNQZ
`XnFc*L 1
U{x'@/Ld
} H\^^p!^)
u32<=Q[
bY<"$);s
/* )sQbDA|p
**SiteInfoBean.java > +SEze
*/ o^ 4+eE
package NetFox; H\S,^)drJ?
iPIA&)x}
BK +JHT
public class SiteInfoBean { L/ZZe5I
]u:NE'0Xy
WRgz]=W3w
private String sSiteURL; //Site's URL u,C-U!A
private String sFilePath; //Saved File's Path 1~*_H_Q't
private String sFileName; //Saved File's Name 1{wy%|H\
private int nSplitter; //Count of Splited Downloading File %6n;B|!
`XD$1>
;8A_-$
public SiteInfoBean() >8VJ!Kg4
{//nSplitter的缺省值为5 <Z5prunov
//default value of nSplitter is 5 LKm5U6
this("","","",5); 9> |rIw
} ^'h~#7s
*D'VW{
7}*5Mir p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j04Q3d \f
{ UeRenp
sSiteURL= sURL; HqbTJ!a
sFilePath = sPath; QW!'A`*x
sFileName = sName; WgIVhj
this.nSplitter = nSpiltter; qjWgyhL
u66w('2
J:>TV.TP
} mMMu'N
5pDxFs=v
bi5'-.B
public String getSSiteURL() >):b AfI
{ l"-D@]"
return sSiteURL; n;MoMGnPh,
} iU3co|q7
GY!&H"%
{S}/LSNB
public void setSSiteURL(String value) -uh/W=Q1R
{ LvR=uD
sSiteURL = value; snK/,lm.
} 0 cQf_o
mr;WxxO5
0}ZuF.
public String getSFilePath() cO<x:{`
{ Fb_~{q
return sFilePath; <sPB|5Ak
} I5e!vCG)
Mn=_lhWK
fN&O `T>
public void setSFilePath(String value) /qz(ra
{ `0so)2ty+
sFilePath = value; s^AYPmR6
} {!,+C0
0D\FFfs
u-?&~WA
public String getSFileName() >s{[d$
{ l[ L{m7
return sFileName; "zqt'b0bW
} `aC#s3[
VA]%i P,O-
kt@+UK."
public void setSFileName(String value) Q8P;AN_JS
{ $k!t&G
sFileName = value; 3Y=S^*ztd
} YX~H!6l
Wima=xYe\5
v"s}7trWV
public int getNSplitter() u2DsjaL
{ \Q#F&q0
return nSplitter; {}.c.W+
} 8`im4.~#%
7`P(LQAr!
]-0 &[@I4@
public void setNSplitter(int nCount) C[[z3tn
{ O ~"^\]\
nSplitter = nCount; l lQ<x
} 8sL7p4
} pa.W-qyu
'vh:(-
(g
/* Z3I<
**Utility.java uD+;5S]us
*/ }+u<^7$g|
package NetFox; lfCoL@$6D
DTJ~.
ov?>ALRg
public class Utility { &gq\e^0CRZ
$biCm$a
inp=-
public Utility() hLBX,r)u
{ &oAuh?kTq
d,$[633It}
[t0gXdU6
} @O4m-Oosi
^d!-IL_
//线程睡眠 398%16}
public static void sleep(int nSecond) &ts!D!Hj
{ ZY{,//
try{ 8pPAEf
Thread.sleep(nSecond); iS02uVmBZ
} d]+g3oy `
catch(Exception e) TlM ]d;9G
{ ]x~H"<V
e.printStackTrace (); eoow]me
} In]h+tG?rN
} +8v!vuO'
Rg'1 F
//日志 *-gS u
public static void log(String sMsg) Ib]{rmaP
{ <Y9ps`{}:
System.err.println(sMsg); ;c~6^s`2
} z%]~^k8
HHT K{X+
0hCJovSG%
public static void log(int sMsg) \O@,v0?R
{ ba|~B8rII[
System.err.println(sMsg); mM>{^%2Q:
} hO\_RhsRy?
} iv\?TAZC
NNSn]LP
1vi<@i,
/* IL`5RZi1
**TestMethod.java _ 4pBJOJQ6
*/ S+_}=25
package NetFox; 6?z&G6
_! \X>rfz
N!aV~\E
public class TestMethod { s+^YGB
V/<dHOfR\
Spt[b.4mF
public TestMethod() zN*/G6>A
{ ///xx/weblogic60b2_win.exe ;OE{&
try{ Peh(*D{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1u'x|Un
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V_(lZDjh*
SiteFileFetch fileFetch = new SiteFileFetch(bean); qFt%{~a S
fileFetch.start(); p%_r0
} ,NPU0IDG>
catch(Exception e){e.printStackTrace ();} ct fKxGH
&KX|gB'
ngn%"xYX
} yUqvF6+26
9^)ochY3
ey@y?X=
public static void main(String[] args) XBdC/DM[
{ X Oc0j9Oa
new TestMethod(); {FteQ@(
} Y?R;Y:u3Z
} `%"zq"1`0
点击下载更多相关资料