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)); 3+3m`%G
} Ra5'x)m36)
for(int i=0;i<nEndPos.length-1;i++) ~ fEs!hl
{ sRQh~5kM
nEndPos = nStartPos[i+1]; fR4l4 GU?)
} M7R&J'SAY
nEndPos[nEndPos.length-1] = nFileLength; 7[BL 1HI*
} |nN/x<v
} n-3j$x1Ne
wG5RN;`V
)V3(nZY
//启动子线程 h(Ed%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =jc8=h[F<
for(int i=0;i<nStartPos.length;i++) V1)P=?%(US
{ lmKq xs4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I&8SP$S>J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2j7d$y*'
nStartPos,nEndPos,i); %J7mZB9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SRN9(LN
fileSplitterFetch.start(); ]t)M}^w
} *g4Cy8$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ""3m!qn#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PbUcbb17
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :ZS8Zm"
nEndPos = " + nFileLength); |.O!zRm
// fileSplitterFetch[nPos.length-1].start(); 9jGuelwN
n/oipiYx
d[e:}1
//等待子线程结束 |$w={N^4
//int count = 0; FJ~_0E#L
//是否结束while循环 :$i:8lz
boolean breakWhile = false; MW$H/:3
@:+n6
U?fN3
while(!bStop) H r^15
{ )_*a7N!
write_nPos(); |sqo+E
Utility.sleep(500); H!r Kz
breakWhile = true; =+}}Sv2
BrH;(*H)8
I.+)sB?5
for(int i=0;i<nStartPos.length;i++) ClMtl59
{ *C@[5#CA2z
if(!fileSplitterFetch.bDownOver) P!+nZXo
{ A?D"j7JD=L
breakWhile = false; 0tCOb9
break; .(7C)P{.0
} x56 F
} r@[VY g~
if(breakWhile) xSDE6]
break; x*&&?nV Iz
#VdI{IbW
M=[q+A
//count++; PR@4' r|a
//if(count>4) 7s8<FyFsjd
// siteStop(); R #3Q$
} m>+,^`0
R g0 XW6
4nII/cPG
System.err.println("文件下载结束！"); z[\W\g*|ri
} FW)^O%2s
catch(Exception e){e.printStackTrace ();} I0w@S7
} ?[S >&Vq
@SC-vc
sb|3|J6=
//获得文件长度 Q;XHHk
public long getFileSize() O<dZA=Oez
{ p~q_0Pg%
int nFileLength = -1; RUk<=!U
try{ ()C^ta_]
URL url = new URL(siteInfoBean.getSSiteURL()); g)9JO6]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Krr?`n
httpConnection.setRequestProperty("User-Agent","NetFox"); $}^\=p}X
I*W9VhIOV
@ojg`!,
int responseCode=httpConnection.getResponseCode(); h76NR
if(responseCode>=400) Dl zmAN
{ Sz|Y$,
processErrorCode(responseCode); 85%Pq:E
return -2; //-2 represent access is error u1;e*ty
} X(!AI|6Bt
we\b]
2JA&{ch
String sHeader; %<wQ
u3M`'YCb
^\vfos
for(int i=1;;i++) zY+t,2z
{ | 3N.5{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v$)@AE
//Utility.log(in.readLine()); /=muj9|+s
sHeader=httpConnection.getHeaderFieldKey(i); D]pK=247
if(sHeader!=null) s-GleX<
{ b#p~F}qT
if(sHeader.equals("Content-Length")) S:p.W=TAB
{ q: Bt]2x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); //X e*0
break; ti{H(;;@
} ?)?IZ Qj
} V#zhGAMy.
else kJurUDo
break; 3{Ek-{9
} JA?,0S
} a(}VA|l
catch(IOException e){e.printStackTrace ();} +q #Xy0u
catch(Exception e){e.printStackTrace ();} A]Q1&qM%
mEB2RLCM
|5O >>a()
Utility.log(nFileLength); Et}C`vZ+Ve
~mXZfG/D
l:zU_J6
return nFileLength; .#=j <&
} 23}BW_m
(o x4K{
2vqmsl?
//保存下载信息（文件指针位置） *Z]5!$UpC
private void write_nPos() (#j2P0B
{ t+=12{9;f
try{ Ad]<e?oN=
output = new DataOutputStream(new FileOutputStream(tmpFile)); ']d!?>C@o
output.writeInt(nStartPos.length); jiA5oX^g
for(int i=0;i<nStartPos.length;i++) 4Vu'r?
{ _W@,@hOH
// output.writeLong(nPos); fa!3/X+
output.writeLong(fileSplitterFetch.nStartPos); lFp!XZ!
output.writeLong(fileSplitterFetch.nEndPos); f MY;
} ).0V%}>
output.close(); *? K4!q'
} a%7"_{s1
catch(IOException e){e.printStackTrace ();} 1<LC8?wt
catch(Exception e){e.printStackTrace ();} ;[{:'^n
} 9RG\UbX)^|
N,j>;x3xT
s{(ehP.Dd
//读取保存的下载信息（文件指针位置） -1jjB1
private void read_nPos() `e'G.@
{ .k# N7[q=
try{ -yX.Jv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); CRZi;7`*1
int nCount = input.readInt(); -`zG_]=-
nStartPos = new long[nCount]; 0Jm]f/iZ
nEndPos = new long[nCount]; do:QH.q8)
for(int i=0;i<nStartPos.length;i++) CS~=Z>6EjA
{ uY&=eQ_Cb
nStartPos = input.readLong(); >DDQ'W!
nEndPos = input.readLong(); !lR0w|
} E$]a?uA:
input.close(); m>]>$=%
} gCv"9j<j
catch(IOException e){e.printStackTrace ();} Dk)@>l:gI,
catch(Exception e){e.printStackTrace ();} `fQM
} :D"@6PC]
;Y Dv.I
Ms.PO{wb
private void processErrorCode(int nErrorCode) R#Y50hzT
{ IXGW2z;
System.err.println("Error Code : " + nErrorCode); [ 3$.*
} =E;=+eqt
jA4PDHf+
2Ryp@c&r^
//停止文件下载 xK$}QZ)
public void siteStop() /a@ kS
{ Y3-]+y%l
bStop = true; q{a#HnZo"
for(int i=0;i<nStartPos.length;i++) e{,!|LhpQ
fileSplitterFetch.splitterStop(); Z:I*y7V-
}Q/G &F
B }6Kd
} ~_ *H)|
} $Llta,ULE
//负责部分文件的抓取 .D+RLO z
**FileSplitterFetch.java F|ETug n
*/ 3H1Pp*PH
package NetFox; .|T2\M
*Y8XP8u/
jMK3T
import java.io.*; %/P=m-K
import java.net.*; 0;}Aj8Fle
KuA>"X
6dF$?I&
public class FileSplitterFetch extends Thread { D~Z=0yD
?#?e(mpo
g<fP:/
String sURL; //File URL $np=eT)
long nStartPos; //File Snippet Start Position T}UT7W|
long nEndPos; //File Snippet End Position 7nm}fT z7
int nThreadID; //Thread's ID &kb\,mQ
boolean bDownOver = false; //Downing is over ^rL,&rk
boolean bStop = false; //Stop identical v#zPH5xo
FileAccessI fileAccessI = null; //File Access interface !]yQ1@)*'
rqF"QU=l
f:xUPH?+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [1NaH
{ i#k-)N _$
this.sURL = sURL; u0xQ;BQ
this.nStartPos = nStart; *]5z^> q;7
this.nEndPos = nEnd; ]K7`-p~T
nThreadID = id; x7f:F.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1:_=g#WH
} USprsaj
~u!gUJ:
j5zFDh1(
public void run() o"RJ.w:dn
{ T$u~E1
while(nStartPos < nEndPos && !bStop) 9x(}F<L
{ pL~=Z?(B
JfkTw~'R
2sUbiDe-
try{ q?yMa9ZZky
URL url = new URL(sURL); ?!H)zz6y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :.DI_XN`
httpConnection.setRequestProperty("User-Agent","NetFox"); @YCv
String sProperty = "bytes="+nStartPos+"-"; 82|q7*M*.
httpConnection.setRequestProperty("RANGE",sProperty); 2\5cjdy
Utility.log(sProperty); 85} ii{S
bjlkX[{}I
PT+c&5AS
InputStream input = httpConnection.getInputStream(); <9`?Z-lJP
//logResponseHead(httpConnection); H-Pq!9[DB
+5-]iKh
[@<G+j
byte[] b = new byte[1024]; Ih()/(
int nRead; ?ZaD=nh$mK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )=Zsv40O
{ Q&gPa]z]}
nStartPos += fileAccessI.write(b,0,nRead); 847 R
//if(nThreadID == 1) rCE;'? Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -1CEr_(P^
} tn{8u7
~5ubh2{
O^0"
Utility.log("Thread " + nThreadID + " is over!"); pisB,wP$2
bDownOver = true; v J-LPTB
//nPos = fileAccessI.write (b,0,nRead); 6|^0_6_
} 7WP%J-
catch(Exception e){e.printStackTrace ();} \6:>{0\
} q`[K3p
} .gq(C9<B[
k}zd' /b
xg} ug[
//打印回应的头信息 \yG`Sfu2
public void logResponseHead(HttpURLConnection con) <m0{'xw
{ Oqmg;\pm
for(int i=1;;i++) U*qNix
{ sMm/4AY]
String header=con.getHeaderFieldKey(i); 7@IFp~6<qK
if(header!=null) EE]=f=3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .'/l'>
Utility.log(header+" : "+con.getHeaderField(header)); b_=8!Q.:
else f>z`i\1oO
break; zKxvN3!
} {5-zyE
} *NlpotW,f
&6/%kkv
-`Q}tg>cT
public void splitterStop() AK*N
{ HIGNRm
bStop = true; m?;$;x~Dj
} %2D17*eK
ej52AK7
jo_ sAb
} E:w:4[neh
Qn.[{rw
P"F{=\V1`<
/* q}wj}t#
**FileAccess.java c 0-w6
*//文件访问(定位，写) A,BEKjR~J
package NetFox; -72j:nk
import java.io.*; Yj|]Uff8O
x2k*|=$
JUQg 'D
public class FileAccessI implements Serializable{ HabzCH
@Tr&`Hi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M3(k'q7&:
RandomAccessFile oSavedFile; h$ Da&$uyI
long nPos; >zmzK{A=
a4&:@`=
gvyT-XI
public FileAccessI() throws IOException 8Z#21X>
{ O@jqdJu
this("",0); S;=_;&68?
} =j~Q/-`EC0
=Ndli>x}1
+O+<Go@a
public FileAccessI(String sName,long nPos) throws IOException V"#Jk!k9k
{ Au5rR>W
oSavedFile = new RandomAccessFile(sName,"rw"); 6peyh_
this.nPos = nPos; ZJ(rG((!
oSavedFile.seek(nPos); os$nL'sq
} O?ktWHUx
=& -[TPW
OOB^gf}$'
public synchronized int write(byte[] b,int nStart,int nLen) zZ=$O-&%
{ YH\j@^n
int n = -1; |pW\Ec#(
try{ {Q~7M$
oSavedFile.write(b,nStart,nLen); Hm9<fQuM
n = nLen; A-wRah.M
} [w+Q^\%bN
catch(IOException e) hNbIpi=
{ >]&X ^V%Q#
e.printStackTrace (); |^GyH$.
} XP?*=Z]
</s,pe79B
maC>LBa2/
return n; >"("*3AO
} w`gyE 6A
r,xmEj0E
G{RTH_p
} Mw^*yW
M35Ax],:^
Bo r7]#
/* y3IWfiz>/d
**SiteInfoBean.java ssl&5AS
*/ 8h.V4/?
package NetFox; ^%#grX#
'Kz9ygZy
{'R)4hL
public class SiteInfoBean { 'jvpNn
JsQ6l%9
kX2d7yQZz
private String sSiteURL; //Site's URL l,d,T
private String sFilePath; //Saved File's Path 6RK\}@^=K
private String sFileName; //Saved File's Name "!Lkp2\
private int nSplitter; //Count of Splited Downloading File :a3xvN-l
[B9;?G
- k`.j
public SiteInfoBean() "C74
{//nSplitter的缺省值为5 =|SdVv
//default value of nSplitter is 5 4#)6.f~
this("","","",5); &ao(!/im
} @Zm Jz
;>ozEh#8w
s".HEP~]=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,W*H6fw+
{ 1 Z[f {T)
sSiteURL= sURL; kMxjS^fr
sFilePath = sPath; Gvx[8I
sFileName = sName; _x %1F
this.nSplitter = nSpiltter; *Km7U-BG
w>979g
'*R%^RK
} 4%_M27bu[
R^8{bP
^}>/n. %
public String getSSiteURL() [,g~m9
{ &mkpJF/
return sSiteURL; ;/sHWI f+Z
} Cs1>bpY*R6
n&!+wcJ;Yt
SSmHEy*r)
public void setSSiteURL(String value) JP'= UZ'
{ ^oeJKjJ
sSiteURL = value; %Q4i%:Qi
} ngUHkpYS5
m{(+6-8|m
NP_?f%(
public String getSFilePath() K ,isjh2
{ `|Fp^gM
return sFilePath; ;n*J$B
} =2 jhII
J?Iq9f
$f-hUOuyo
public void setSFilePath(String value) edpW8eND
{ (3%t+aqq
sFilePath = value; 5Op_*N{V
} 3!#/k+,C
EW(J5/mn
`9 [i79U
public String getSFileName() 'uC59X4l
{ !O)qYmK]|
return sFileName; y0IK,W'&?
} $[(d X!]F
?L|yaC~
+AI`R`Tm
public void setSFileName(String value) 0I%: BT
{ QK <\kVZ8
sFileName = value; ]WL|~mG
} h-XY4gq/
NFyMY#\]
>K:u?YD[
public int getNSplitter() F ?=9eISLJ
{ !%S4n
return nSplitter; }ugxN0
} d2jr8U
5*G%IR@@LK
Qv{,wytyO
public void setNSplitter(int nCount) >*qQ+_
{ , =y#m-9
nSplitter = nCount; ClQe4uo{
} -%m3-xZA
} 5PiOH"!19
W{Z^n(f4
;l!`C':'
/* jP=Hf=:$
**Utility.java qd6fU^)i
*/ JYmAn?o-
package NetFox; GyC)EFd
+5X DF
\l,rpVv5m
public class Utility { 5%i:4sMx *
Oh; Jw
<kc#thL
public Utility() =G${[V\
{ .SS<MDcqIt
r>|-2}{N/
@;)PSp*j
} ;y1Q6eN
=8JB8ZFP
//线程睡眠 p2 !FcFi
public static void sleep(int nSecond) YpmYxd^
{ HW6.O|3
try{ ..qd,9H
Thread.sleep(nSecond); r>n" 51*
} a.kbov(
catch(Exception e) &ab|2*3?X
{ +%#8k9Y
e.printStackTrace (); l-O$m
} l]!B#{
} pv# 2]v
0A[esWmP
//日志 #kcSQ'
public static void log(String sMsg) >k(MUmhX
{ s~L</Xvo
System.err.println(sMsg); 7P**:b
} <$i4?)f(
<bUe/m
,+1m`9}
public static void log(int sMsg) X.#oEmA,P
{ NiSO'=y$n
System.err.println(sMsg); Xe1P- 60
} ^&[+H8$
} ")UwkF
~[W#/kd1n
s"~5']8
/* PLR0#).n
**TestMethod.java &|o$=Ad
*/ *l+Cl%e
package NetFox; wpo1
1mgLX_U9
hYg'2OG
public class TestMethod { kfrY1
elO<a]hX
W>-B [5O&[
public TestMethod() 4na8
{ ///xx/weblogic60b2_win.exe x]4Kkpqm
try{ ?J!3j{4e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *yaw$oB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QU5Sy oL[
SiteFileFetch fileFetch = new SiteFileFetch(bean); >fs2kha
fileFetch.start(); ukAKFc^)k
} q{' ~+Nq
catch(Exception e){e.printStackTrace ();} < n?=|g
cy3Td28,
EbK0j?
} &t}?2>:
\~DM
p]gT&[iJ
public static void main(String[] args) :E_a0!'
{ j,-C{ K
new TestMethod(); /iQ(3F
} }*wLEa
} {^ec(EsO#
点击下载更多相关资料