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)); p2O~>97t1
} u$*>`Xe6
for(int i=0;i<nEndPos.length-1;i++) nzsl@1s
{ %J7UP4
nEndPos = nStartPos[i+1]; .#w6%c@
} lK(Fg
nEndPos[nEndPos.length-1] = nFileLength; e XV@.
} \k@$~}xD,
} -n))*.V
Z~u9VYi!
uO(w1Q"^
//启动子线程 B!S167Op
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )u} Q:`9
for(int i=0;i<nStartPos.length;i++) {=Q7m`1
{ _GA$6#]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ([E]_Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A o/vp-e
nStartPos,nEndPos,i); Z S|WnMH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M"Y0jQ(
fileSplitterFetch.start(); "lVqU
} l|"6yB |
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [M+tB"_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,T5u'";
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I0Ia6w9
nEndPos = " + nFileLength); ?ny=
// fileSplitterFetch[nPos.length-1].start(); HZjf`eM,
S\ ,mR4:
4_=Ja2v8;`
//等待子线程结束 nWYCh7
//int count = 0; %JL]; 4'
//是否结束while循环 KtN&,C )lJ
boolean breakWhile = false; w=_Jc8/.
"VUYh$=[
! fl4"
while(!bStop) dF@)M
{ IApT'QNM
write_nPos(); >,5i60Q
Utility.sleep(500); [ !%R#+o=F
breakWhile = true; u'5`[U -!
2Aq~D@,9=:
}VCI=?-
for(int i=0;i<nStartPos.length;i++) ?UZ?NY
{ Ao.\
if(!fileSplitterFetch.bDownOver) `N87h"
{ blt'={Z?.x
breakWhile = false; 8*a), 3aK
break; pbk$o{$`W
} l]LxL
} 4ne5=YY*
if(breakWhile) 9<1F[SS<s9
break; TJ_=1Y@z
X`r*ob
:}}%#/nd
//count++; Qyh/ed/
//if(count>4) kI\tqNJi
// siteStop(); hf<J \
} QfpuZEUK
Hh[Tw&J4
lFG9=Wf
System.err.println("文件下载结束！"); Y%`SHe7M
} 1T|$BK@)
catch(Exception e){e.printStackTrace ();} 4`v!Z#e/aX
} LDj<?'
oOU1{[
Pcd *">v
//获得文件长度 0~WF{_0|
public long getFileSize() J5p8nmb
{ gBw^,)Q{0Y
int nFileLength = -1; '?5j[:QY@
try{ -apXI.
URL url = new URL(siteInfoBean.getSSiteURL()); tD=@SX'Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L=!of{4Z(}
httpConnection.setRequestProperty("User-Agent","NetFox"); NTs7KSgZ
vp)Vb^K>
/YKMKtE
int responseCode=httpConnection.getResponseCode(); OYL]j{
if(responseCode>=400) E#%}ZY
{ S -&)p@4
processErrorCode(responseCode); 9q[;u[A8^
return -2; //-2 represent access is error W[''Cc.
} !7p}C-RZp
2b@tj 5
|F$BvCg
String sHeader; ,_v|#g@{
n.6T OF
iAn'aW\TF
for(int i=1;;i++) Gpj* V|J
{ pHE}ytcT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Yc Q=vt{
//Utility.log(in.readLine()); K`%tGVY
sHeader=httpConnection.getHeaderFieldKey(i); _'0 @%P%
if(sHeader!=null) X"asfA[6K
{ },-*
if(sHeader.equals("Content-Length")) Tenf:Hm/k
{ wEft4o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'o4p#`R:8
break; :*i f
} {<$bAj
} f'En#-?O
else <E,%@
break; r|<DqTc6l
} Ww3wsyx
} 2B1xUj ]
catch(IOException e){e.printStackTrace ();} yJx?M
catch(Exception e){e.printStackTrace ();} VU.@R,
>7Jr^o#|_x
EM j;2!
Utility.log(nFileLength); BzJ;%ywS
A&5:ATQ/|
.)XP\m\
return nFileLength; @I3eK^#|P
} GRqT-/n"
77 r(*.O|
vG.9H_&
//保存下载信息（文件指针位置） T3%C%BcX
private void write_nPos() 5r,r%{@K
{ .10y0FL4
try{ 8AFczeg[[
output = new DataOutputStream(new FileOutputStream(tmpFile)); IND]j72
output.writeInt(nStartPos.length); 9]'&RyH=#
for(int i=0;i<nStartPos.length;i++) I~* ? d
{ (<*e
// output.writeLong(nPos); R=j% S!
output.writeLong(fileSplitterFetch.nStartPos); BHFY%6J!
output.writeLong(fileSplitterFetch.nEndPos); }CGSEr4'w~
} Cr ?4Ngw
output.close(); v}JD2.O+
} cQj-+Tmu
catch(IOException e){e.printStackTrace ();} +/{L#e>
catch(Exception e){e.printStackTrace ();} H1:be.^YP
} wNJzwC&iQ
Vy<HA*
xG2F!WeF
//读取保存的下载信息（文件指针位置） o:q1beU
private void read_nPos() t~7V{ xk
{ z;\dL
try{ bO5k6i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w(d>HHg
int nCount = input.readInt(); L5YnG_M&
nStartPos = new long[nCount]; Ucw yxXI
nEndPos = new long[nCount]; _Xcn N:Rt
for(int i=0;i<nStartPos.length;i++) `\u;K9S6
{ GbP!9I
nStartPos = input.readLong(); [V8fu qE>
nEndPos = input.readLong(); E-5_{sc
} E ]9\R
input.close(); F/c$v
} (@0O
catch(IOException e){e.printStackTrace ();} &[mZD,
catch(Exception e){e.printStackTrace ();} ./6<r OW
} 0C%W&;r0
eJCjJ)
6vKS".4C
private void processErrorCode(int nErrorCode) una%[jTc
{ nKr9#JebRC
System.err.println("Error Code : " + nErrorCode); K4Dp:2/K%
} |]=2 }%1w
Q _iO(qu 6
WG71k8af
//停止文件下载 \G@wp5
public void siteStop() Q^Ql\
{ kzmQm
bStop = true; I`(l*U
for(int i=0;i<nStartPos.length;i++) G_H?f\/
fileSplitterFetch.splitterStop(); VhGs/5
/t<@"BoV
m#/_x
} <+j)P4O4
} penlG36Q
//负责部分文件的抓取 P,S G.EFK
**FileSplitterFetch.java >ydRSr^
*/ hg@}@Wq\)
package NetFox; K0+.q?8D|
E\8
b,TiMf9},h
import java.io.*; 1SIq[1
import java.net.*; r,P1^uHx
2aA`f7
Uggw-sRU
public class FileSplitterFetch extends Thread { ~tFqb<n
<|Yj%f
qZEoiNH(Tj
String sURL; //File URL M6r^L6$N
long nStartPos; //File Snippet Start Position wd@aw/
long nEndPos; //File Snippet End Position ^rl"rEA
int nThreadID; //Thread's ID s MN*RKer
boolean bDownOver = false; //Downing is over r`S< A;
boolean bStop = false; //Stop identical &ZHC-qMRK
FileAccessI fileAccessI = null; //File Access interface )}%O>%
AdZ;j6#
s pLZ2]A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #%@*p,xh
{ nwt C:*}
this.sURL = sURL; nP~({:l8X
this.nStartPos = nStart; `IpA.| Y
this.nEndPos = nEnd; 5v\!]?(O;
nThreadID = id; ma$Prd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !}+tdT(y
} |wE3UWsy
|H}m4-+*
2f`nMW
public void run() YT/kC'A
{ _/*U2.xS
while(nStartPos < nEndPos && !bStop) ^>y@4qB
{ 2 !" XzdD
c)md
$/1c= Y@
try{ $2DuB
URL url = new URL(sURL); )\;Z4x;]U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i|)Su4Dw
httpConnection.setRequestProperty("User-Agent","NetFox"); 6&Juv
String sProperty = "bytes="+nStartPos+"-"; 5m:i6,4
httpConnection.setRequestProperty("RANGE",sProperty); L(>=BK*
Utility.log(sProperty); g @I6$Z
dUznxZB
Hy"x
InputStream input = httpConnection.getInputStream(); ,fIe&zq
//logResponseHead(httpConnection); oY~ Dg
~n')&u{
Z4$cyL'$P
byte[] b = new byte[1024]; [ =x s4=
int nRead; 4F>Urh+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t&Os;x?To?
{ /y7M lU9
nStartPos += fileAccessI.write(b,0,nRead); E@05e
//if(nThreadID == 1) W>(/ bX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ./j,Z$|
} vzel#
Y!q!5Crfi
-V"22sR]
Utility.log("Thread " + nThreadID + " is over!"); Hd7,ZHj3^
bDownOver = true; I2$T"K:eo
//nPos = fileAccessI.write (b,0,nRead); $GQ`clj<
} _sE#)@p
catch(Exception e){e.printStackTrace ();} @;xMs8@
} I|-p3g8\
} ?;YC'bF
@pI5lh
C'=k&#<-
//打印回应的头信息 {y]mk?j
public void logResponseHead(HttpURLConnection con) '$As<LOEd/
{ Q(d9n8
for(int i=1;;i++) rKHY?{!
{ q{2I_[p
String header=con.getHeaderFieldKey(i); }ZSQ>8a
if(header!=null) ffXyc2o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GT hL/M
Utility.log(header+" : "+con.getHeaderField(header)); /:6Wzj
else 6J~12TU,
break; X1[CX&Am
} j#~Jxv%n
} 22<0DhJ
?.c;oS|
+#b:d=v!
public void splitterStop() 0c.s -
{ `s '#
bStop = true; t&5%?QyM
} be5,U\&z
VN0mDh?E
iVFkYx%}
} nhSb~QqEh
04%S+y.6&Y
&|%6|u9
/* ]`g<w#
**FileAccess.java fl Jp4-nx
*//文件访问(定位，写) YJs|c\eq?
package NetFox; IC{eE
import java.io.*; y~ G.V,0
=Cv/Y%DN
,<<4*
public class FileAccessI implements Serializable{ p5O",3,A4
bsxTqJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #>Y'sd5'A
RandomAccessFile oSavedFile; vhvdKD
long nPos; 6*l^1;U
cH<q:OYi
gef6pfV
public FileAccessI() throws IOException `G1&Z]z
{ 2eeQ@]Wj[Z
this("",0); kVI#(uO
} E$a ?LFa6
(3[z%@I
7@.cOB`y@3
public FileAccessI(String sName,long nPos) throws IOException P3 c\S[F
{ <]C$xp<2
oSavedFile = new RandomAccessFile(sName,"rw"); Nf3.\eR
this.nPos = nPos; Bb&^{7
oSavedFile.seek(nPos); G>YAJo
} (vR 9H(#
a</D_66
?Y:x[pOe
public synchronized int write(byte[] b,int nStart,int nLen) ;)Kh;;e
{ vN4Qdpdb
int n = -1; =5D nR
try{ PqNFyQkl
oSavedFile.write(b,nStart,nLen); <)g8yA
n = nLen; Ae^X35
} @ZN^1?][
catch(IOException e) 3$vRW.c\q
{ Md)zEj`\
e.printStackTrace (); !KKT[28v
} 2=-utN@Z
m6eZ_&+u
q0%
return n; wn Y$fT9
} at!Y3VywG
l?Y_~Wuw
^^i6|l1
} *?QE2&S:
syx\gz
G.+l7bnZM
/* B)$c|dUV
**SiteInfoBean.java WWwUwUi
*/ a/~aFmu6b
package NetFox; =k}SD96
3`O?16O
X u"R^
public class SiteInfoBean { )f+U~4G&
TUL_TR
0Q"u#V Sp
private String sSiteURL; //Site's URL @L84>3O
private String sFilePath; //Saved File's Path #6+FY+/
private String sFileName; //Saved File's Name rA0,`}8\
private int nSplitter; //Count of Splited Downloading File bf_I9Z3m
NRnRMY-
0U66y6
public SiteInfoBean() -71dN0hWh
{//nSplitter的缺省值为5 -B#yy]8
//default value of nSplitter is 5 g]*
this("","","",5); /Y[~-Y+!,
} PIA)d-Z
qo+N,x9o
&m3.h!dq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BE&B}LfvfO
{ Xqp|VbDca
sSiteURL= sURL; A]`El8_t"
sFilePath = sPath; })vOaYT|-
sFileName = sName; !.7udYmB
this.nSplitter = nSpiltter; D0Z\Vvy
He0=-AR8
ufa41$B'yG
} ]"AyAkT(
QVZD/shq
d "BW/%m|g
public String getSSiteURL() @Un/c:n
{ r#WT`pav
return sSiteURL; va/m~k|i
} HLQ"?OFlz
w&Dv8Wv+Oq
`T/~.`R
public void setSSiteURL(String value) LW#M@
{ SEQ%'E5-'
sSiteURL = value; T1B|w"In
} ZWc+),X
s30 O@M))
P7r'ffA
public String getSFilePath() O9v_y+M+M
{ Mr+@c)
return sFilePath; < V\Y@Ei+
} 7RU}FE
~:;3uLs,8
*, Ld/O;s
public void setSFilePath(String value) (dJI_A
{ N\t1T(C|
sFilePath = value; -0o[f53}p
} Auy".br'
'2J0>Bla
/4=-b_2Y~
public String getSFileName() y#ON|c /
{ pl*~kG=
return sFileName; rgIrr5
} fLN!EDq
VeiElU3
&zL#hBE
public void setSFileName(String value) Zr$d20M2A;
{ (%ew604X
sFileName = value; TGT$ >/w >
} @mw "W{
~CRSL1?
(lA.3 4.p
public int getNSplitter() VCNT4m
{ Mro4`GL
return nSplitter; NCeaL-y7
} {!ZyCi19
*E>.)B i
!}TMiCK
public void setNSplitter(int nCount) c"YXxAJ
{ g]mtFrP
nSplitter = nCount; s}M= oe
} cl[!`Z
} #~:P}<h
KcGsMPJ
wn+FTqj
/* +%J\y^09kr
**Utility.java X[C3&NX#_
*/ }6RT,O g
package NetFox; 8$P>wCK\l
LDT(]HJ
ZU'!iU|8
public class Utility { KV!<Oq
AH7L.L+$M
\L!uHAE2a
public Utility() r2*<\ax
{ Zp`T
khd5 Cf[
MKGS`X]<J
} XaI;2fMGI
AG"l1wz
//线程睡眠 BW[5o3 i
public static void sleep(int nSecond) >.9eBz@
{ ( `' 8Ww
try{ 8 ,}ikOZ?
Thread.sleep(nSecond); #5CI)4x0!
} Ayx^Wp*s
catch(Exception e) Eyh|a.)-
{ I %_MV
e.printStackTrace (); ~2}Pl)
} <)m%*9{
} ,4F,:w
Evu=M-?
//日志 _j#SpL'P
public static void log(String sMsg) Rc$h{0K8
{ 9w~cvlv[
System.err.println(sMsg); y>o>WN<q
} V2znU
A=3HO\n5
h* .w"JO
public static void log(int sMsg) a0_(eO-S
{ jp<VK<s]
System.err.println(sMsg); $3 8gs{+
} ~uaP$*B[
} crmUrF#
D5A=,\uk
L'kq>1QWf
/* 1M5 -pZ[D
**TestMethod.java WYIw5jzC
*/ 7[o {9Yp&
package NetFox; |HbEk[?^s
(!zM\sF
:$H!@n*/R
public class TestMethod { Ti= 3y497S
-CBD|fo[h
YdOUv|tZC
public TestMethod() }B)jq`a?|\
{ ///xx/weblogic60b2_win.exe d'zT:g
try{ aWvd`qA9r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &hN,xpC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fj=NiZ=
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9YC&&0 C@
fileFetch.start(); pMN<p[MB
} `SOhG?Zo
catch(Exception e){e.printStackTrace ();} LM1b I4
'j79GC0
%W;u}`
} k&GHu0z
a!t V6H
*T4ge|zUc
public static void main(String[] args) 5u,sx664
{ R;THA!
new TestMethod(); JSjYC0e
} q|{tQJfYg
} Z{}+)Q*Q
点击下载更多相关资料