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)); F_}y[Yn^
} } ?+0s=Z
for(int i=0;i<nEndPos.length-1;i++) I_Gm2Dd
{ q|lP?-j
nEndPos = nStartPos[i+1]; !t)uRJ
} {)Zz4
nEndPos[nEndPos.length-1] = nFileLength; iF:NDqc
} +5GC?cW
} EN>a^B+!
4dz Ym+vJm
Uu`}| &@i
//启动子线程 !}eq~3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M.$=tuUL
for(int i=0;i<nStartPos.length;i++) o9{1_7K
{ s}^W2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j)mS3#cH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #5{lOeN
nStartPos,nEndPos,i); Q\^BOdX^`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4/x.qoj
fileSplitterFetch.start(); wqE2n
} =xH>,-8}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZTGsZ}{5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qc 1mR\.5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _=qk.|p/
nEndPos = " + nFileLength); +jGUp\h%9;
// fileSplitterFetch[nPos.length-1].start(); Vx n-
1ww~!R
&9n=!S'Md
//等待子线程结束 ;[,#VtD
//int count = 0; 2Aq+:ud)P
//是否结束while循环 !uKuO
boolean breakWhile = false; z)&&Ym#
]V"B`ip[2
lb)i0`AN+
while(!bStop) w 3L+7V,!
{ @^Kw\s
write_nPos(); QSo48OFs
Utility.sleep(500); ]`@<I'?,X
breakWhile = true; ehX4[j6
KXo[;Db)k
4d-"kx3X
for(int i=0;i<nStartPos.length;i++) 6A} 45
{ BLo=@C%w5
if(!fileSplitterFetch.bDownOver) "L)?dlb6T
{ Nu}Zsb|{
breakWhile = false; {f>e~o
break; ]"vpCL
} nlx~yUXL4
} j+3=&PkA.]
if(breakWhile) )5U7w
break; [4}U*\/>C
*_uGzGB&G
];Bk|xJ/>
//count++; qS[nf>"
//if(count>4) kPp7;U2A
// siteStop(); 6)3pnhG9
} 74~%4
Xu[A,6
o l+*Oe
System.err.println("文件下载结束！"); SM`n:{N(
} .ffb*gZ4
catch(Exception e){e.printStackTrace ();} W%}zwQ
} Nu%MXu+
sTYA
qP[jtRIN
//获得文件长度 y-:d`>b>\
public long getFileSize() (Mt-2+"+
{ f@xjNm*'Z
int nFileLength = -1; K~\Ocl
try{ i"y @Aj!7
URL url = new URL(siteInfoBean.getSSiteURL()); oSs~*mf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !o`h*G-x
httpConnection.setRequestProperty("User-Agent","NetFox"); #Bas+8 @,
LZ~}*}jy
meyO=>
int responseCode=httpConnection.getResponseCode(); ;U<rFs40
if(responseCode>=400) Qnv)\M1
{ 5q.)K f+
processErrorCode(responseCode); zAd%dbU|
return -2; //-2 represent access is error )>^!X$`3
} sMWNzt
y)+lU
h!]=)7x;
String sHeader; i}LVBx"K(
Bjsg!^X7
\w@ "`!%
for(int i=1;;i++) ,S=ur%
{ Md1ePp]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oei2$uu
//Utility.log(in.readLine()); #;>v,Jo
sHeader=httpConnection.getHeaderFieldKey(i); 8Nf%<nUv
if(sHeader!=null) /:aY)0F0<&
{ YZ^;xV
if(sHeader.equals("Content-Length")) ft4(^|~
{ 32,Y3!%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )Es|EPCx!
break; sxU 0Fg
} kR;Hb3hb
} QpMi+q Y
else um1xSf1Xv
break; kG3m1: :
} QetyuhS~
} _{YUWV50}
catch(IOException e){e.printStackTrace ();} IX 2 dic'
catch(Exception e){e.printStackTrace ();} =$Sd2UD
O/PO?>@-/
6^"Spf]
Utility.log(nFileLength); </jTWc'}
qgw)SuwW
77p8|63
return nFileLength; Dt*/tVF
} 3etW4
@ M
o0F&,|'
//保存下载信息（文件指针位置） 5TS&NefM
private void write_nPos() W 33MYw
{ #w#:f
try{ 4:Id8rzz
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?=0BU}
output.writeInt(nStartPos.length); h_K!ch}
for(int i=0;i<nStartPos.length;i++) JWvL
{ c^EU&q{4
// output.writeLong(nPos); F>s5<pKAX
output.writeLong(fileSplitterFetch.nStartPos); ,ftKRq
output.writeLong(fileSplitterFetch.nEndPos); #hF(`oX}4K
} @j=Q$k.GF
output.close(); jS| 9jg:
} zP|^) h5
catch(IOException e){e.printStackTrace ();} <K zEn+
catch(Exception e){e.printStackTrace ();} ,FDRU
} MON]rj7
)TzQ8YpO}
6ly`lu9
//读取保存的下载信息（文件指针位置） n]fMl:77
private void read_nPos() wj<fi
{ 6k*,Yei
try{ Ni-@El99
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @pO2A6Ks
int nCount = input.readInt(); 4|Ay;}X \
nStartPos = new long[nCount]; #8qhl
nEndPos = new long[nCount]; .FpeVjR''
for(int i=0;i<nStartPos.length;i++) ?I332,,q
{ T43Jgk,
nStartPos = input.readLong(); GEUC<bL+
nEndPos = input.readLong(); S<UWv@`U"
} 0;2"X[e
input.close(); @PAT|6
} 2*ByVK
catch(IOException e){e.printStackTrace ();} ;HoBLxb P
catch(Exception e){e.printStackTrace ();} .l$:0a
} 5v,_ Hgh
R-J^%4U`7
w0`8el;
private void processErrorCode(int nErrorCode) #l#8-m8g)
{ ?]PE!7H
System.err.println("Error Code : " + nErrorCode); ?n(OH~@$i
} +Un(VTD
yU'<b.]
Ws*UhJY<GS
//停止文件下载 =a^}]k}
public void siteStop() :.aMhyh#*
{ p;n"zr8U
bStop = true; 2v?fbrC5c
for(int i=0;i<nStartPos.length;i++) D,P{ ,/
fileSplitterFetch.splitterStop(); JK'FJ}Z4
l~Rd\.O
szC<ht?z
} X)b@ia'"Wp
} 7B{LRm6;Vu
//负责部分文件的抓取 2R];Pv
**FileSplitterFetch.java 8(ej]9RObU
*/ )J{.z
package NetFox; |Q+:vb:
HvzXAd
jH>`:
import java.io.*; v8f1o$R
import java.net.*; _=-B%m
V;29ieE!
3>QkO.b
public class FileSplitterFetch extends Thread { w?:tce
@A'@%Zv-
'M!M$<j
String sURL; //File URL a]nK!;>$
long nStartPos; //File Snippet Start Position ?/|KM8
long nEndPos; //File Snippet End Position '8w>=9Xl
int nThreadID; //Thread's ID a&RH_LjM
boolean bDownOver = false; //Downing is over )9i$ 1"a(
boolean bStop = false; //Stop identical MUn(ZnQy|
FileAccessI fileAccessI = null; //File Access interface z}w7X6&e
#pcgfVl
`IV7\}I|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R9\ )a2
{ y4)iL?!J~
this.sURL = sURL; M>[e1y>7
this.nStartPos = nStart; z"P/Geb:O
this.nEndPos = nEnd; +h08uo5c
nThreadID = id; nM|Cv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E.N
} #f<3[BLx
y#zO1Nig`
Z5|BwM
public void run() 7>lM^ :A
{ .F},Z[a&
while(nStartPos < nEndPos && !bStop) [h63*&
{ Z7XFG&@6
T.}Y&,n$$5
F.),|t$\
try{ s@IgaF {
URL url = new URL(sURL); }`.d4mm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &EmG\vfE
httpConnection.setRequestProperty("User-Agent","NetFox"); gCq'#G\Z
String sProperty = "bytes="+nStartPos+"-"; T>68 ,; p
httpConnection.setRequestProperty("RANGE",sProperty); ,&.$r/x|?
Utility.log(sProperty); +/ rt'0o
C),i#v
2Gh&h(
InputStream input = httpConnection.getInputStream(); lg +>.^7k
//logResponseHead(httpConnection); JED\"(d(
YD;G+"n?T
\@[,UZ
byte[] b = new byte[1024]; T~L&c
int nRead; e|N~tUVrrN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R$X~d8o>%
{ O,JS*jXl
nStartPos += fileAccessI.write(b,0,nRead); GZ^Qt*5 {
//if(nThreadID == 1) T@A Qe[U'v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *:"@
} :gO5#HIm
/>6ECT
m!5Edo-;<
Utility.log("Thread " + nThreadID + " is over!"); u}b%-:-
bDownOver = true; >x>/}`
//nPos = fileAccessI.write (b,0,nRead); 9dmoB_G
} u'nQC*iJb
catch(Exception e){e.printStackTrace ();} $,P:B%]
} J$5Vjh'aM
} %&S9~E D
2VzYP~Jg
#q4uS~
//打印回应的头信息 df!i}L
public void logResponseHead(HttpURLConnection con) ^t:dcY7
{ 2RQ-L
for(int i=1;;i++) PV:J>!]
{ F$bV}>-1k
String header=con.getHeaderFieldKey(i); 7[PEiAI
if(header!=null) A=3L_ #nO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :bm%f%gg
Utility.log(header+" : "+con.getHeaderField(header)); &d0sv5&s
else 4jt(tZS
break; mRa\ wEg%
} 0<O()NMv
} )2_[Ww|.
c]zFZJ6M
NBHpM}1xtU
public void splitterStop() Uo71C4ev
{ `BVmuUMm
bStop = true; FgL892[
} 7i!VgV
!I.}[9N
'%82pZ,?
} Nte$cTjX
#*:^\z_Jd
$xWUzg1<U
/* Qe{w)e0}`
**FileAccess.java `XpQR=IOMb
*//文件访问(定位，写) z$WLx
package NetFox; k/D{&(F ~
import java.io.*; 5'c#pm\Q
4Y$\QZO
le]~Cy0
public class FileAccessI implements Serializable{ :eSsqt9]9
&7oL2Wf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7[w<v(Rc
RandomAccessFile oSavedFile; - Z`RKR8C
long nPos; H>A6VDu
IzJq:G.
9v[V"m`M
public FileAccessI() throws IOException N!Rt040.%
{ }zx ~
this("",0); VX&PkGi?o
} QeG9CS)E}j
|?ssHW
!~yBzH;K
public FileAccessI(String sName,long nPos) throws IOException fum.G{}
{ Z Cjw)To(
oSavedFile = new RandomAccessFile(sName,"rw"); U2A 82;Z
this.nPos = nPos; L-!1ybB^
oSavedFile.seek(nPos); (v%24bv
} Q{RmE:
H=Ilum06
KVJ, a
public synchronized int write(byte[] b,int nStart,int nLen) (Xcy/QT
{ ? ep#s$i
int n = -1; i5t6$|u:&m
try{ f+Sb>$
oSavedFile.write(b,nStart,nLen); -~|{q)!F
n = nLen; c#sHnpP
} YT Zi[/
catch(IOException e) o]Rlivahm
{ d.^g#&h
e.printStackTrace (); (XQuRL<X
} 6:O<k2=2
}}{n|l+R5
8v4 o+wP
return n; #5Z`Q^
} IF|6iKCE
yjg&/6
6FQi=}O1
} 8.#{J&h
s:Ml\['x
+7^p d9F.
/* 1J4Pnl+hN
**SiteInfoBean.java -(8I?{"4i
*/ :t{~Mi=T
package NetFox; ]MV8rC[\
<aJQV)]\
wDZ<UP=X
public class SiteInfoBean { 67YC;J]n=z
o^\Pt<~W
0(D^NtB7
private String sSiteURL; //Site's URL /v8Q17O?e
private String sFilePath; //Saved File's Path 4 "HX1qP
private String sFileName; //Saved File's Name 1!~cPD'F
private int nSplitter; //Count of Splited Downloading File Y~-y\l;Tr
Ve3z5d:^
UtQey ;w
public SiteInfoBean() >F7w]XH
{//nSplitter的缺省值为5 >sfg`4
//default value of nSplitter is 5 >H!Mx_fDL
this("","","",5); BVNW1<_:
} V@G#U[D
N8b\OTk2
fI613ww]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hTr5Q33y>
{ .h7s.p?
sSiteURL= sURL; g[3LPKQ
sFilePath = sPath; ]R#:Bq!F
sFileName = sName; ~ELMLwn.
this.nSplitter = nSpiltter; [|DKBJ
8AuBs;i
] 3"t]U'f
} c+9L6}D
6<._^hyq
"6$V1B0KW
public String getSSiteURL() MC}t8L=
{ @1JwjtNk
return sSiteURL; hj [77EEz
} - {QU>`2
l@4_D;b3o"
udZOg
public void setSSiteURL(String value) ;Y$>WKsV
{ &12KpEyf
sSiteURL = value; _\ToA9m
} sjr,)|#[
;uUFgDi
:8A+2ra&
public String getSFilePath() Ey&H?OFiP
{ d;Vy59}eY
return sFilePath; G%<}TI1}
} Nr~$i%[
N{;!xIv
;sZG=y@
public void setSFilePath(String value) /\I6j;$z
{ ;]>kp^C#
sFilePath = value; E-bswUVaEE
} z)qYW6o%
tS'lJu
/ (&E
public String getSFileName() Oj5UG*
{ jT{T#_
return sFileName; %ou,|Dww
} `>gG"1,]
wA"@t
'o>)E>
public void setSFileName(String value) K}~$h,n
{ zX>W 8P
sFileName = value; >lQo _p(;
} x sryXex;
I`kfe`_
9DxHdpOk
public int getNSplitter() `8:)? 0Ez
{ zfIo]M`
return nSplitter; O VV@
} m[9.'@ye
: \+xXb{
>XD?zF)6
public void setNSplitter(int nCount) Ott6y
{ 5)k8(kH
nSplitter = nCount; uN|A}/hr]
} pP. _%5
} d7OygDb<
MMM tB6
7L{1S v
/* `fu_){
**Utility.java @I_cwUO
*/ I{Zb/}k-
package NetFox; RLmOg{L
^X=Q{nB
y+k_&ss
public class Utility { !#tVQ2O
&`"DG$N(
IC`3%^
public Utility() diq}\'f
{ D'" T'@
BuJo W@)
$ V^gFes
} p@m0Oi,=
z:Ml;y
//线程睡眠 bz4Gzp'6k
public static void sleep(int nSecond) Hq3|>OqC2Q
{ *LT~:Gs#
try{ _5oTNL2
Thread.sleep(nSecond); F^i3e31*t
} d+9V% T
catch(Exception e) ]ss[n.T0*
{ zA,vp^
e.printStackTrace (); CWj_K2=d
} Av X1*
} N'Gq9A
XHr*Rs.[=
//日志 w+M/VsL
public static void log(String sMsg) Wh[QR-7Ew
{ [BWq9uE
System.err.println(sMsg); 54 lD+%E
} ]%\,.&=hT
`KJ(.m
SQp|
public static void log(int sMsg) ( xs'D4
{ pGbfdX
System.err.println(sMsg); !ifU}qFzK
} DeO-@4+qKd
} FXQWT9Kk~_
ke4E1T-1n
LCF}Y{
/* j]u!;]
**TestMethod.java \Z-th,t
*/ y7Po$)8l
package NetFox; 3uL f0D
F'bwXb**
}K{1Bm@S
public class TestMethod { iHa?b2=)
=u.@W98, K
E$d#4x
public TestMethod() 5E!C?dv(z
{ ///xx/weblogic60b2_win.exe &5CRXf
try{ 5ut| eD`3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L*@`i ]jl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3Cf9'C
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5cSiV7#Y:
fileFetch.start(); b?H"/Mu.
} |;ztK[(
catch(Exception e){e.printStackTrace ();} c4JV~VS+
j-<]OOD
]vrZGX a+
} ER0 Yl
du65=w4E!
?OD$`{1
public static void main(String[] args) ]#tB[G
{ L9GLjRp-
new TestMethod(); :@A&HkF
} u'YXI="(
} x/|W;8g4
点击下载更多相关资料