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)); 1lv.@-
} lIatM@gU
for(int i=0;i<nEndPos.length-1;i++) "Z a}p|Ct
{ 5PKdMEK|q
nEndPos = nStartPos[i+1]; E{B40E~4
} =XUt?5
nEndPos[nEndPos.length-1] = nFileLength; myZ8LQ&
} z-kB!~r
} YtT:\#D
rf2-owWN
4?7OP t6
//启动子线程 O~F8lQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %e=UYBj"
for(int i=0;i<nStartPos.length;i++) Y}Nd2
{ ?uE@C3 e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1ZfhDtK(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -s6;IoG/
nStartPos,nEndPos,i); Snas:#B!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g6q67m<h
fileSplitterFetch.start(); ] 2lhJ
} @p7*JLO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F[oTc^dr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0^ $6U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F:2V;
nEndPos = " + nFileLength); }?%5Ae7l,
// fileSplitterFetch[nPos.length-1].start(); r1xhplHH@
-;[,`g(f
%R*-oQ1T
//等待子线程结束 yLCJSN$7
//int count = 0; &28%~&L
//是否结束while循环 ^@xn3zJ
boolean breakWhile = false; f(*^zga,
)}R w@70L-
E`UEl$($
while(!bStop) nOUF<DNQ
{ !\1Pu|
write_nPos(); k*= #XbX
Utility.sleep(500); @RI\CqFHR
breakWhile = true; ~YrO>H` B
'sTMUPg`
*8xMe
for(int i=0;i<nStartPos.length;i++) 1"} u51
{ 8|\?imOp\[
if(!fileSplitterFetch.bDownOver) 5]@"f/
{ H5p&dNO
breakWhile = false; g=n /w
break; A{QA0X!p
} Q|:qs\6q5
} s4{>7`N2
if(breakWhile) Ba]^0Y u
break; [5Pin>]z
2t"&>1
Z\*jt B:
//count++; co%-d
//if(count>4) $<s 3;>t
// siteStop(); %C(^v)"
} [cf!%3>53
I>z0)pB
i6D66E
System.err.println("文件下载结束！"); 5KDN8pJN
} "\M^jO
catch(Exception e){e.printStackTrace ();} K)r|oW=6Y
} p v*n.U6
$/;;}|hqi
InR/g@n+D1
//获得文件长度 d,caOE8N
public long getFileSize() JQ]A"xTIa*
{ 4z>SI\Ss
int nFileLength = -1; 924a1
try{ H{j jA+0
URL url = new URL(siteInfoBean.getSSiteURL()); E?[]N[0Kl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `%S#XJU
httpConnection.setRequestProperty("User-Agent","NetFox"); %w3"B,k'9D
Omy<Y@$
"AUHe6Yv
int responseCode=httpConnection.getResponseCode(); .=<<b|
if(responseCode>=400) ?mJ&zf|B8
{ 0Wc8\c
processErrorCode(responseCode); !qF t:{-h
return -2; //-2 represent access is error Z`Sbq{Kx
} L4-v'Z;
2io~pk>
MF/@Efjn ]
String sHeader; &i?>mt
zsuXN*
Ub-q0[6
for(int i=1;;i++) $z5
{ eJwHeG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }:a:E~5y
//Utility.log(in.readLine()); 8[xl3=
sHeader=httpConnection.getHeaderFieldKey(i); 8xN+LL'T{
if(sHeader!=null) @Lf-=9
{ g<$q#l~4xH
if(sHeader.equals("Content-Length")) :J6lJ8w ?
{ $c<NEt_\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U[t/40W}P
break; xb~8uD5
} |Y&&g=7
} yRv4,{B}X>
else G2BB]] m3
break; Kk9W=vd
} s'Wu \r'
} n!$zO{P
catch(IOException e){e.printStackTrace ();} ];8S<KiS~
catch(Exception e){e.printStackTrace ();} .DG`~Fpk
_[t:Vme}v
7@uhw">mX
Utility.log(nFileLength); ?,0 a#lG
*$yU|,
cHjnuL0fsy
return nFileLength; qaZQ1<e
} p]erk
$Cx?%X^b
GjH$!P=.
//保存下载信息（文件指针位置） Js}1_K
private void write_nPos() ni`uO<\U
{ {ZIEIXWb2
try{ R7ze~[oF
output = new DataOutputStream(new FileOutputStream(tmpFile)); J_rb3
output.writeInt(nStartPos.length); I$HO[Z!
for(int i=0;i<nStartPos.length;i++) ^^Te
{ @K=C`N_22
// output.writeLong(nPos); >JckN4v
output.writeLong(fileSplitterFetch.nStartPos); {~cM 6W]f
output.writeLong(fileSplitterFetch.nEndPos); :ExCGS[
} zqt{oN_
output.close(); Sahz*f
} ptMDhMVW
catch(IOException e){e.printStackTrace ();} e-Ma8+X\
catch(Exception e){e.printStackTrace ();} qbD>)}:1
} ykat0iqo
oo2CF!Xy
<<l1zEf@
//读取保存的下载信息（文件指针位置） YgL{*XYAt
private void read_nPos() >PmnR>x-rj
{ S";c7s
try{ 7X`]}z4g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !THa?U;
int nCount = input.readInt(); c%@< h6
nStartPos = new long[nCount]; '4"c#kCKL
nEndPos = new long[nCount]; S-%itrB*
for(int i=0;i<nStartPos.length;i++) [2\jQv\Y
{ v1}9i3Or#
nStartPos = input.readLong(); ~6Pv5DKq
nEndPos = input.readLong(); 8$`$24Wx
} ^n~bx*f
input.close(); 1'4?}0Dok
} )/cf%
catch(IOException e){e.printStackTrace ();} [D_s`'tg
catch(Exception e){e.printStackTrace ();} hh7unHt-
} (bp4ly^
|e{ ^Yf4
^aR^M\38
private void processErrorCode(int nErrorCode) []b= xRJM
{ T7R,6qt
System.err.println("Error Code : " + nErrorCode); r%\%tz'`j
} eY\w?pT2
$q*hE&x Qd
pPsT,i?
//停止文件下载 I_\?wSNGM
public void siteStop() ^2C \--=;
{ yIYQ.-DkS+
bStop = true; MnTJFo"
for(int i=0;i<nStartPos.length;i++) !q!5D`
fileSplitterFetch.splitterStop(); h,|. qfUk
7A"v:e
z9Nial`p
} <%?!3 n*
} G3dA`3
//负责部分文件的抓取 4t,f$zk
**FileSplitterFetch.java w:aV2
*/ A9Icn>3?`(
package NetFox; S\L^ZH?[2
zS*vKyye>
weC.kx
import java.io.*; TpcJ1*t
import java.net.*; i F \H
Ruv`yfQ
)~-r&Q5d
public class FileSplitterFetch extends Thread { 7sq15oL
z-N N(G+
>!MRk[@ V-
String sURL; //File URL QD^q\9U[
long nStartPos; //File Snippet Start Position (;9j#x
long nEndPos; //File Snippet End Position `*",_RO;
int nThreadID; //Thread's ID >u+%H vzc
boolean bDownOver = false; //Downing is over |eI!wgQx
boolean bStop = false; //Stop identical p^k*[3$0
FileAccessI fileAccessI = null; //File Access interface Zu/w[*;M
)F+wk"`+6
p|g7Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G@P+M1c
{ m:6*4_!
this.sURL = sURL; \+j:d9?
this.nStartPos = nStart; ),J6:O&
this.nEndPos = nEnd; +CN!3(r
nThreadID = id; ~9Qd83`UH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M>d^.n
} 4JRQ=T|P7I
zZ94_8b
08+\fT [
public void run() 5,J.$Sax
{ tMH2
while(nStartPos < nEndPos && !bStop) M|fC2[]v B
{ B`)TRt+'.
fd$nAE
@MP;/o+
try{ 9[R+m3V/`
URL url = new URL(sURL); +GncQs y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p z\8Bp}yo
httpConnection.setRequestProperty("User-Agent","NetFox"); Q^*4FH!W
String sProperty = "bytes="+nStartPos+"-"; Irui{%T
httpConnection.setRequestProperty("RANGE",sProperty); <%.lPO]&E
Utility.log(sProperty); t;V^OGflv
L7[f-cK2:
gx8i|]
InputStream input = httpConnection.getInputStream(); Tvt(nWn(H1
//logResponseHead(httpConnection); P9W?sPnC5
t;`ULp~&
5zOC zm
byte[] b = new byte[1024]; mt~E&Z(A
int nRead; Qb|@DMq%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .bUj
{ Mm;[f'{M)
nStartPos += fileAccessI.write(b,0,nRead); 3&6sQ-}*
//if(nThreadID == 1) \5}*;O@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _2hZGC%&E
} @z^7*#vQv
U/-k'6=M
KL./
Utility.log("Thread " + nThreadID + " is over!"); gC(@]%
bDownOver = true; 2fg P
//nPos = fileAccessI.write (b,0,nRead); 0BH-kr
} (/FG#D.
catch(Exception e){e.printStackTrace ();} ]=PkgOJD
} h>F"GR?U_(
} q4v:s
5O;D\M{>
l#~pK6@W
//打印回应的头信息 M%WO
public void logResponseHead(HttpURLConnection con) j2%fAs<
{ @}2EEo#
for(int i=1;;i++) 51tZ:-1!
{ |{JI=$
String header=con.getHeaderFieldKey(i); Shv$"x:W
if(header!=null) OZA^L;#>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V"B/4v>
Utility.log(header+" : "+con.getHeaderField(header)); qeb}~FL"o
else C-\3,
break; xIwILY|W=
} O`5hjq#
} +cM~|
h^ K]ASj
[N#4H3GM8
public void splitterStop() Km,%p@`m
{ 6AoKuT;
bStop = true; IJVzF1vC
} [] el4.J,
lF t^dl^
?C- ju8]|
} U1(cBY
v!$:t<-5N
mT #A?C2
/* Z*ag{N
**FileAccess.java W23Q>x&S
*//文件访问(定位，写) Te`@{>
package NetFox; TV#>x!5!d
import java.io.*; TY%=Y=
B3pjli
iXq*EZb"R
public class FileAccessI implements Serializable{ *Q)-"]O(k
" %qr*|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :K5?&kT
RandomAccessFile oSavedFile; wWSo+40
long nPos; 1xu~@v60
]s!id[j
^!x! F
public FileAccessI() throws IOException 8]oolA:^4s
{ "0,FB4L[U5
this("",0); '1(6@5tyWk
} mHV{9J
R:3=!zav
IRueq @4
public FileAccessI(String sName,long nPos) throws IOException Nukyvse
{ V]GF53D
oSavedFile = new RandomAccessFile(sName,"rw"); ^tjw }sE
this.nPos = nPos; ! ,{zDMA
oSavedFile.seek(nPos); S^;;\0#NK
} ~$C}?y^ a
9 )!}
|28'<BL
public synchronized int write(byte[] b,int nStart,int nLen) ,iY:#E
{ ;9~ WB X"
int n = -1; pwkTe
try{ ~)n[Vf
oSavedFile.write(b,nStart,nLen); <*WGvCh%w
n = nLen; 3fA+{Y8S
} X6T[+]Gc
catch(IOException e) TZ `Ypi7r
{ 1uppE|
e.printStackTrace (); i]J.WFu
} _RbM'_y+E
>{9VXSc
!tcz_%
return n; k5J18S
} dpK-
G.^)5!By
QqRF?%7q"q
} '2hy%
2g~ @99`
: p)R,('g
/* ij!],
**SiteInfoBean.java D4C:%D
*/ 7qZC+x6_L
package NetFox; -FI)o`AE
}2;iIw`
<:NahxIlu
public class SiteInfoBean { B-$?5Ft!
%l14K_
+2}cR66%
private String sSiteURL; //Site's URL [ZC\8tP`V
private String sFilePath; //Saved File's Path 93:oXyFjD
private String sFileName; //Saved File's Name 97$Q?a8S@
private int nSplitter; //Count of Splited Downloading File KO%$
W$2\GPJt
2K{'F1"RM
public SiteInfoBean() _x1W\#
{//nSplitter的缺省值为5 ~,E }^
//default value of nSplitter is 5 l U8pX$
this("","","",5); @;$cX2
} :CK`v6 Qs
S89j:KRXH%
3 o$zT9j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +RJKJ:W
{ WJu(,zM?G
sSiteURL= sURL; 5S2 j5M00
sFilePath = sPath; ]z5hTY
sFileName = sName; rMHh!)^#W
this.nSplitter = nSpiltter; 9(OeH7
T/2k2r4PD
]jC{o,?s
} h#KSKKNW
eY'nS
4L ]4WVc
public String getSSiteURL() `GW&*[.7
{ iw=e"6V
return sSiteURL; sNcU>qjj6
} p JT)X8K"
/]'&cD 1
od5nRb
public void setSSiteURL(String value) m;\nMdn
{ jf`w8*R
sSiteURL = value; =}kISh
} mXyN{`q=
4w=v /WDo
z-b78A/8
public String getSFilePath() 8a`3eM~?[
{ RXg\A!5GV
return sFilePath; |aAyWK S
} -j]c(Q MA]
`B4Ilh"d
~3M8"}X;L
public void setSFilePath(String value) {6GX ?aw'
{ 7M7Lj0Y)L
sFilePath = value; 8/(}Wet
} >l><d!hw
wdfbl_`T
iQ(j_i'+!I
public String getSFileName() _pZ <
{ 1.k=ji$D0
return sFileName; |9\i+)C
} k ,ldi
G+Z ,ic
sR>>l3H
public void setSFileName(String value) fS/:OnH
{ M>Tg$^lm
sFileName = value; }2LWDQ;po
} vs[!B-
D (8Z90
UkpTK8>&
public int getNSplitter() *]NfT}}
{ "_\"S
return nSplitter; fdX|t"oz
} ][tR=Y#&y5
hU-FSdR
`|>]P"9yp
public void setNSplitter(int nCount) Hzm_o>^KC
{ b@8z+,_
nSplitter = nCount; cZ|NGkZ
} ga/zt-&
} z9 Ch %A{
~cSXBc,+
du$M
/* ?%$O7_ThvA
**Utility.java M1Ff ,]w
*/ ,cS#
package NetFox; &'&)E((
aVK,(j9u
mj e9i
public class Utility { s|A[HQUtJ
}q]*aADe
}A@:JR+|
public Utility() W)bSLD
{ f3G:J<cL
&U?4e'N)T
Z8FgxR
} <!FcQVH+L
]s0wJD=
//线程睡眠 zps=~|
public static void sleep(int nSecond) SyI~iW#Y1
{ Qt{){uE
try{ iTq&h=(n
Thread.sleep(nSecond); Y)F(-H)
} Z81;Y=(
catch(Exception e) SO *oBA'
{ =TNFAt
e.printStackTrace (); HM0&%
} WwTl|wgvyI
} M>m!\bb%.
@@K/0:],
//日志 Vdxo
public static void log(String sMsg) `r-Jy{!y4
{ vJGH8$%;,
System.err.println(sMsg); /huh}&NNu
} FCEmg0qdjD
"Y L^j~A
t?-a JU
public static void log(int sMsg) d3q.i5']G
{ Qd YYWD
System.err.println(sMsg); u28$V]
} JD0s0>q_
} aV|VC$
cL*oO@I&_
9#P~cW?
/* y7:f^4
**TestMethod.java n.8870.BW
*/ ![ce }
package NetFox; y[.lfW?)
EGqu-WBS
UakVmVN/P
public class TestMethod { C=r`\W
)#i"hnYpQ
Y% \3N
public TestMethod() beikzuC
{ ///xx/weblogic60b2_win.exe HP_h!pvx
try{ )e'F[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #z&R9$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6M7GPHah
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0n6eWwY
fileFetch.start(); R[l`# I
} w (RRu~J
catch(Exception e){e.printStackTrace ();} GB}\7a
HAI)+J
%vy,A*
} Gr&e]M[l
de2G"'F
fi>.X99(G
public static void main(String[] args) 7Ko*`-p
{ 'D`lVUB
new TestMethod(); qGV(p}$O
} B,_K mHItd
} E_A5KLP
点击下载更多相关资料