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)); gi$'x^]#
} s01=C3
for(int i=0;i<nEndPos.length-1;i++) vb3hDy
{ |\W~+}'g~
nEndPos = nStartPos[i+1]; ZtY?X- 4_
} -FW^fGS+
nEndPos[nEndPos.length-1] = nFileLength; 0 gR_1~3
} c[Z#q*Q
} _%(.OR
X2'XbG3
B_>r|^Vh
//启动子线程 I8k+Rk*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p$cb&NNh*H
for(int i=0;i<nStartPos.length;i++) zF(abQ0
{ v>_83P`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }:(;mW8 D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ??lsv(v-
nStartPos,nEndPos,i); >X*Y jv:r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TSVlZy~Xo
fileSplitterFetch.start(); dFmpx%+p
} )>@%;\qV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %!8w)1U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LIT`~D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )&l5I4CIf
nEndPos = " + nFileLength); <r m)c.
// fileSplitterFetch[nPos.length-1].start(); H-mQ{K^
4gZ)9ya
WJMmt XO
//等待子线程结束 @^GI :z
//int count = 0; J0B*V0'zR
//是否结束while循环 uvJ&qd8M
boolean breakWhile = false; M*D@zb0ia
00@F?|-j
PcI~,e%
while(!bStop) .9?GKD
{ 2#N?WlYw<S
write_nPos(); ~y"OyOi&
Utility.sleep(500); Uyxn+j5
breakWhile = true; JP^\
trB-(B%5
|>'q%xK
for(int i=0;i<nStartPos.length;i++) \fp'=&tp~a
{ X*9-P9x(6
if(!fileSplitterFetch.bDownOver) 5rmQ:8_5
{ }$g"|;<ha
breakWhile = false; N-q6_
break; F{c8{?:
} .1z=VLKF'
} .{|SKhXk
if(breakWhile) f4&;l|R0a
break; r$Ni>[as
^%tn$4@@Z.
VTY #{
//count++; yXqC
//if(count>4) Z4E6J'B8
// siteStop(); i0*Cs#(=h
} b"nkF\P@Fj
6ND*L0
reM~q-M~o@
System.err.println("文件下载结束！"); fRq+pUxU
} DLD9
catch(Exception e){e.printStackTrace ();} ,_s.amL3O{
} u%Mo.<PI
mn*}U R
Z
//获得文件长度 \DWKG~r-%
public long getFileSize() L,ax^]
{ J3e'?3w[
int nFileLength = -1; h:sf?X[
try{ g"kET]KP"
URL url = new URL(siteInfoBean.getSSiteURL()); U#Iwe=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0C\cM92o
httpConnection.setRequestProperty("User-Agent","NetFox"); k8@bQ"#b
Dy8H(_
pp(?rE$S
int responseCode=httpConnection.getResponseCode(); j5A>aj
if(responseCode>=400) TBky+]p@
{ #2$wI^O
processErrorCode(responseCode); ~wOMT
return -2; //-2 represent access is error wXZ9@(^
} qk>SM|{
:RwURv+kT
>< P<k&
String sHeader; f9 :=6
hJ8%r_
:>Qu;Z1P
for(int i=1;;i++) G)c+GoK
{ c5:0`~5Fn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SuNc&e#(
//Utility.log(in.readLine()); <#199`R
sHeader=httpConnection.getHeaderFieldKey(i); +$xw0)|
if(sHeader!=null) ;' |CSjco
{ ^:mKTiA-
if(sHeader.equals("Content-Length")) TTbJ9O<43
{ U2tgBF?)A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mAY/J0_
break; ~D`R"vzw=
} CfD4m,6
} q?)5yukeF
else _qpIdQBo
break; "gzn%k[D9m
} >Z<ZT
} 1zw,;m n
catch(IOException e){e.printStackTrace ();} a`]ZyG*P
catch(Exception e){e.printStackTrace ();} E>gLUMG$
G#@#j]8
W$&*i1<a+
Utility.log(nFileLength); `ZO5-E
wZbT*rU
l0qHoM,1Y[
return nFileLength; +ZGH
} vRD(* S9^
qW|h"9sr
J7e/+W~
//保存下载信息（文件指针位置） m!!;CbPo
private void write_nPos() k>8OxpaWv?
{ [u J<]
try{ k.Gt}\6zP
output = new DataOutputStream(new FileOutputStream(tmpFile)); gp~-n7'~O
output.writeInt(nStartPos.length); ZtP/|P5@
for(int i=0;i<nStartPos.length;i++) !{ _:k%B
{ -]Mk} z$
// output.writeLong(nPos); rM6S%rS
output.writeLong(fileSplitterFetch.nStartPos); X7:Dw]t
output.writeLong(fileSplitterFetch.nEndPos); Z0D&ayzkh^
} \$t{K
output.close(); Z=%u:K}[
} 4`cfFowK~
catch(IOException e){e.printStackTrace ();} B6\/xKmv?8
catch(Exception e){e.printStackTrace ();} gvo5^O+)HH
} JHVndK4L
{!{T,_ J
;A*sub
//读取保存的下载信息（文件指针位置） 9ao?\]&t
private void read_nPos() xlgT1b:6
{ }g%&}`%'
try{ @y0kX<M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3+:NX6Ewb*
int nCount = input.readInt(); d~QJ}a
nStartPos = new long[nCount]; = 1d$x:
nEndPos = new long[nCount]; >s,*=a
for(int i=0;i<nStartPos.length;i++) 4"{g{8
{ Bxj4rC[
nStartPos = input.readLong(); dr(e)eD(R>
nEndPos = input.readLong(); YhAO
} KK-+vq
input.close(); ZX{eggXl
} w>Ft5"z
catch(IOException e){e.printStackTrace ();} b+Vlq7Bc
catch(Exception e){e.printStackTrace ();} N5k9o:2
} 5`K'2
8-b~p
fg1uqS1rg
private void processErrorCode(int nErrorCode) p{SIGpbR&
{ 'Nx"_jQ
System.err.println("Error Code : " + nErrorCode); m5KLi &R
} Kj6+$l
6jl{^dI
v yP_qG
//停止文件下载 *t={9h
public void siteStop() +,D82V7S
{ +ZBj_Vw*|
bStop = true; :X*uE^bH
for(int i=0;i<nStartPos.length;i++) qrt2uE{K
fileSplitterFetch.splitterStop(); )oS~ish
g)MLgjj
y>RqA*J
} .=c@ps
} W}wd?WIps
//负责部分文件的抓取 -**fT?n
**FileSplitterFetch.java 2Paw*"U
*/ !W=2ZlzS
package NetFox; FOcDBCrOe
I+Fr#1
`]Vn[^?D
import java.io.*; a$6pA@7}
import java.net.*; q#Ik3 5
o`}8ZtD
Pp|pH|(n ,
public class FileSplitterFetch extends Thread { 2L1Azx
ACgWT
RWn#"~
String sURL; //File URL \z2d=E
long nStartPos; //File Snippet Start Position B_.>Q8tK;
long nEndPos; //File Snippet End Position } x'o`GuUf
int nThreadID; //Thread's ID r8L'C
boolean bDownOver = false; //Downing is over `"bp-/
boolean bStop = false; //Stop identical ;[Hrpl S
FileAccessI fileAccessI = null; //File Access interface I]ol[ X0S
q{)Q ?E
+ V-&?E(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E95VR?nUg
{ Y[fbmn^
this.sURL = sURL; sF#t{x/sW
this.nStartPos = nStart; i"hn%u$V
this.nEndPos = nEnd; nSU7,K`PM
nThreadID = id; 2f-Or/v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^#2Y4[@
} ]PXpzruy
^EKf_w-v
2l4`h)_q
public void run() :SpPT
{ B&H [z
while(nStartPos < nEndPos && !bStop) \Ng[lN
{ RjX#pb
=TXc- J
N" oJ3-~
try{ &oiBMk`*
URL url = new URL(sURL); HC ?XNR&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pJwy~ L
httpConnection.setRequestProperty("User-Agent","NetFox"); 22m'+3I~Y
String sProperty = "bytes="+nStartPos+"-"; v_@&#!u`
httpConnection.setRequestProperty("RANGE",sProperty); ZbcpE~<a
Utility.log(sProperty); & |o V\L
fBt7#Tc=U
=t-503e.J
InputStream input = httpConnection.getInputStream(); &rxR"^x\
//logResponseHead(httpConnection); }L*cP;m#
Cqk6Igw
S>p>$m, Q
byte[] b = new byte[1024]; $(%t^8{a~G
int nRead; nyB~C7zR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bpeWK&
{ n7Ia8?8-l
nStartPos += fileAccessI.write(b,0,nRead); bga2{<VF
//if(nThreadID == 1) tMy@'nj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _&m
} \(bML#I
Djf,#&j!3
wA}+E)x/C
Utility.log("Thread " + nThreadID + " is over!"); ffYiu4$m
bDownOver = true; hYNb9^
//nPos = fileAccessI.write (b,0,nRead); VN8ao0^d;d
} 4%k_c79>
catch(Exception e){e.printStackTrace ();} ?wx|n_3<:
} {GiR-q{t
} Z5o6RTi
Z`b{r;`m8
zKk2>.
//打印回应的头信息 oFV>b
public void logResponseHead(HttpURLConnection con) 5q?ZuAAA
{ <&rvv4*H
for(int i=1;;i++) ,9p 4(jjX
{ QY<2i-A
String header=con.getHeaderFieldKey(i); y(8AxsROp
if(header!=null) Pw'3ya8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `=Hh5;ep
Utility.log(header+" : "+con.getHeaderField(header)); 7>J8\=
else (v8jVbg
break; OE/O:F:1j
} S0Y$$r
} X}xy v
`:A`%Fg8<
:_Y@,CpIEg
public void splitterStop() 8:,l+[\
{ GRb"jF>ut
bStop = true; pVt8z|p_;{
} MI@id
DxT8;`I%
A@EeX4N
} p/xxoU
"el}@
F%x8y
/* ?y7x#_Exc
**FileAccess.java (AdQ6eGMb
*//文件访问(定位，写) %@5f+5{i!z
package NetFox; YzSUJ=0/
import java.io.*; { CkxUec
0zaE?dA]
0Q=4{*:?
public class FileAccessI implements Serializable{ @ Sw[+`
q7C>A`w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \&J7>vu^y
RandomAccessFile oSavedFile; !~cTe!T
long nPos; /PAxPZf_
1_!*R]aq
mV} peb
public FileAccessI() throws IOException |Gb"%5YD
{ G_g~-[O
this("",0); 3ADTYt".
} "EQ-`b=I4
*?K3jy{
^PfFW
public FileAccessI(String sName,long nPos) throws IOException z{cIG8z
{ z1?7}9~`0c
oSavedFile = new RandomAccessFile(sName,"rw"); 6yKr5tH4
this.nPos = nPos; 52BlFBNV
oSavedFile.seek(nPos); h&||Ql1
} ;GO>#yg4Eh
74rz~ZM 5
!q! =VC
public synchronized int write(byte[] b,int nStart,int nLen) vDz)q
{ ](4V3w.
int n = -1; V4}9f5FR
try{ ,L^eD>|j5
oSavedFile.write(b,nStart,nLen); Iu^#+n
n = nLen; xCD|UC46?X
} )R+@vh#Q<$
catch(IOException e) a%7ju4CVj
{ xXM`f0s@+]
e.printStackTrace (); Z}TuVE
} {=j!2v#8~
|_8-3
iV[g.sP-
return n; !-%i" a
} ^wCjMi(sj
$ckX H,l_
mF[w-<:.d
} i2A>T/?{
as- Z)h[B
a;D{P`%n
/* c%r?tKG6
**SiteInfoBean.java :f?\ mVS+
*/ gYfN?A*`_
package NetFox; ~T9%%W[
ZFNM>C^
Ey=(B'A~
public class SiteInfoBean { e'mm42
V|ax(tHv
sptDzVM
private String sSiteURL; //Site's URL R_:47.qq
private String sFilePath; //Saved File's Path $&Ng*oX
private String sFileName; //Saved File's Name 2@@OjeANsX
private int nSplitter; //Count of Splited Downloading File 2ixg ix
pI|Lt
c_<m8b{AEF
public SiteInfoBean() `Lb^!6`)
{//nSplitter的缺省值为5 }(z[ rZ
//default value of nSplitter is 5 ifl`QZp_
this("","","",5); @*e|{;X]hy
} A&rk5y;
CTQF+Oe8O
{v+,U}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mufi>}
{ ^AdHP!I
sSiteURL= sURL; OF&{mJH"g'
sFilePath = sPath; #\[h.4i
sFileName = sName; W\:!v%C
this.nSplitter = nSpiltter; orYE&
]l7) F-v
Fxdu)F,~u
} A94ZG:
x1</%y5ev
?pn<lW8d
public String getSSiteURL() c""*Ng*T
{ 2K4Jkyi
return sSiteURL; !|;^
} iz!E1(z(
NFw7g&1;Kp
PnkJWl<S
public void setSSiteURL(String value) &NZl_7PL
{ lx$]f)%~
sSiteURL = value; ]Ir{9EE v
} <qjNX-|
Uyf<:8U\
P,U$ X+
public String getSFilePath() yW5/Y02
{ C4wJSQl_I
return sFilePath; ya7PF~:E-
} &<hDl<E
P"d7Af
XCr\Y`,Z@
public void setSFilePath(String value) 81Ixs Qt
{ yN}upYxp
sFilePath = value; +c;/hM<IX.
} eD5:0;X2
!lQGoXQ'4
"c5C0 pK0
public String getSFileName() 0qP&hybL[(
{ aDEz|>q
return sFileName; wMFo8;L
} 5@l[!Jl0k
?4>uGaU\
-+MGs]),
public void setSFileName(String value) W=b<"z]RE
{ 74f3a|vx/
sFileName = value; FyD^\6/x
} 5'iJN$7
|]=. ^
:eIPPh|\
public int getNSplitter() Xc)V;1
{ fzcPi9+
return nSplitter; &G63ReW7 @
} vn oI.;H,
yLv jfP1
0u0<)gdX
public void setNSplitter(int nCount) cfZG3"
{ dzA5l:5
nSplitter = nCount; yWS#{|o(
} -^A=U7
} n0nf;E
z3F ^OU
#bRr|`
/* e<_yr>9g"
**Utility.java _PTo!aJL
*/ +a'QHtg
package NetFox; ;=rMIi
-Vj'QqZ
Zmx[u_NG
public class Utility { Znl&.,c)
3,`.$
]J=S\
public Utility() w8~J5XS
{ m>po+7"b
i&cH
w1zI"G~4/Q
} lHYu-}TNP
84PD`A
//线程睡眠 K?l1Gj
public static void sleep(int nSecond) V<} ^n
{ 'WqSHb7
try{ ,gU%%>-_~w
Thread.sleep(nSecond); ` eB-C//
} xx}R6VKU.
catch(Exception e) 8ad!.
{ Kd_WN;l
e.printStackTrace (); Ru%: z>Y
} Kuh! b`9
} vFfvvRda4x
C,C=W]G
//日志 <`dF~
public static void log(String sMsg) V/5hEoDt
{ qA- ya6
System.err.println(sMsg); rT`D@ I
} oz}p]l7
Xco$ yF%
FswMEf-|
public static void log(int sMsg) 1B3,lYBM
{ "?j|;p@!>
System.err.println(sMsg); '-#6;_ i<
} 39!o!_g
} b("JgE`
(l22p
?o0#h
/* CiP-Zh[gZ
**TestMethod.java X$JO<@x
*/ .}fc*2.'
package NetFox; =erA.u
\Rn.ug
ADX}
public class TestMethod { \h^bOxh
|Y<ca
<.3@-z>w2,
public TestMethod() +N[dYm
{ ///xx/weblogic60b2_win.exe Fga9
try{ (2@b ,w^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cu({%Gy+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "sFdrXJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); v>3ctP{
fileFetch.start(); ~4}m'#!
} )<.S3
catch(Exception e){e.printStackTrace ();} n#3y2,Ml
\Y9=dE}
HqgTu`
} gx[#@(
5*buRYck0
*Oz5I
public static void main(String[] args) iy tSC
{ sSG]I%oB3
new TestMethod(); ?p5RSt
} v03~=(
} F__>`Dol
点击下载更多相关资料