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)); k}U JVH21k
} V^2-_V]8
for(int i=0;i<nEndPos.length-1;i++) 0bSz4<}
{ 7k~Lttuk
nEndPos = nStartPos[i+1]; 3S;N(A4
} Z2bUs!0
nEndPos[nEndPos.length-1] = nFileLength; I="oxf#q
} cgN>3cE
} M(2`2-/xh
CV3DMA
:Eo8v$W\RB
//启动子线程 nB&j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;wgFr.#hp@
for(int i=0;i<nStartPos.length;i++) t%$@fjz
{ !+KhFC&Py
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [q3+$W \r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^/a*.cu
nStartPos,nEndPos,i); lkwh'@s.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !DcX8~~@
fileSplitterFetch.start(); {cR3.%wX
} y 1nU{Sc@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ag6uR(uI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wDw<KU1UK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )5GQJiY
nEndPos = " + nFileLength); yC"Zoa6YZ
// fileSplitterFetch[nPos.length-1].start(); *<q4S(l
IN_gF_@%
+*.1}r&
//等待子线程结束 EY$?^iS
//int count = 0; P7r4ePtLk{
//是否结束while循环 JJ-i_5\q
boolean breakWhile = false; kFLT!k
U&Ab#m;
zo44^=~%
while(!bStop) R@n5AN(
{ /buWAX1
write_nPos(); ANb"oX c
Utility.sleep(500); }e2F{pQ
breakWhile = true; c,$mWTC
OoM_q/oI
&I)\*Ue2t
for(int i=0;i<nStartPos.length;i++) [%~^kq=|
{ jb3.W
if(!fileSplitterFetch.bDownOver) v$3_o :
{ `xIh\q
breakWhile = false; MA6P"?
break; [+gzdLad
} 0x71%=4H^x
} 74]a/'4
if(breakWhile) WIG=D{\Yx
break; vgo{]:Aj{
VA2<r(y~(
_+n;A46
//count++; WW6yFriuW
//if(count>4) ugxw!cj
// siteStop(); \u8,!) 4i
} HamEIL-l.
oLP]N$'#
Ut_mrb+W
System.err.println("文件下载结束！"); 6|oWaA\gI
} k/bque
catch(Exception e){e.printStackTrace ();} :l`i4kx
} v:A:37#I
5[<F_"x
0#nXxkw
//获得文件长度 @wZ_VE7B
public long getFileSize() Gjh7cm>
{ ;rdLYmmx^
int nFileLength = -1; m1Z8SM+
try{ EqU[mqeF
URL url = new URL(siteInfoBean.getSSiteURL()); 'bO? =+c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9r*T3=u.S
httpConnection.setRequestProperty("User-Agent","NetFox"); 4T^WRS
\ku{-^7
tzN;;h4C
int responseCode=httpConnection.getResponseCode(); 74OM tLL$
if(responseCode>=400) PiQs><FK8
{ ';V+~pi
processErrorCode(responseCode); P &._-[
return -2; //-2 represent access is error LA Vgf>
} (3*Hl
m$: a|'mS
$B/cj^3
String sHeader; 7FFYSv,[:
C#0Wo
l.)!jWY
for(int i=1;;i++) )gF9D1eA
{ o%5Ao?z~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FvP1;E
//Utility.log(in.readLine()); b)@x@3"O
sHeader=httpConnection.getHeaderFieldKey(i); W=w@SO_?wp
if(sHeader!=null) V>SA3
{ @jeV[N,0
if(sHeader.equals("Content-Length")) u'>CU
{ "YZ`g}sG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gk`.8o
break; \ed(<e>
} :b-(@a7>
} \_'pUp22
else "de:plMofy
break; iiscm\
} w{IqzmPiH
} ^"-2fJ
catch(IOException e){e.printStackTrace ();} 2S/7f:
catch(Exception e){e.printStackTrace ();} 8uiQm;W
z{x -Vfd
|<$O5b'
Utility.log(nFileLength); jL$X3QS:
h,g~J-x`|
yAe}O#dy
return nFileLength; j!dklQh0
} /2q%'"x(
m|[Hhw=f
<s>SnOD
//保存下载信息（文件指针位置） cs)hq4-L`
private void write_nPos() @P?*<b{
{ [R$4n-$
try{ M\3!elp2z
output = new DataOutputStream(new FileOutputStream(tmpFile)); =Ju}{ bX
output.writeInt(nStartPos.length); *XuzTGa"
for(int i=0;i<nStartPos.length;i++) lki(_@3
{ ,D1QJPM
// output.writeLong(nPos); b3H;Ea?^^<
output.writeLong(fileSplitterFetch.nStartPos); 3@PVUJ0B|
output.writeLong(fileSplitterFetch.nEndPos); lk|/N^8M
} _U %B1s3y
output.close(); zFIbCv8
} r%4:,{HF
catch(IOException e){e.printStackTrace ();} sr4K-|@
catch(Exception e){e.printStackTrace ();} % |V:F.f
} whshjl?a
hS Sq=(S
(_2eiE71
//读取保存的下载信息（文件指针位置） )I@iW\`7
private void read_nPos() ]@EjKgs
{ =0S7tNut
try{ eYFCf;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vs+N{ V
int nCount = input.readInt(); iBQftq7
nStartPos = new long[nCount]; +t f=
nEndPos = new long[nCount]; 2B#\683
for(int i=0;i<nStartPos.length;i++) Wo&i)S<i0F
{ +x`tvo
nStartPos = input.readLong(); ]?2AFkF
nEndPos = input.readLong(); BLRrHaX0
} .|K5b]na
input.close(); -{?Rq'H
} T!n<ya!
catch(IOException e){e.printStackTrace ();} S$Wd}2>
catch(Exception e){e.printStackTrace ();} ;iEqa"gO
} ^U1;5+2G+~
wBf bpoE7
<NUZPX29
private void processErrorCode(int nErrorCode) xucV$[f
{ ,AJd2ix
System.err.println("Error Code : " + nErrorCode); 0o#lB^e;l
} -`( :L[
)S]c'}^
0 [s1!Cm!i
//停止文件下载 eu~;G H
public void siteStop() w v1R ]3}
{ ixp%aRRP
bStop = true; /w|YNDA]j
for(int i=0;i<nStartPos.length;i++) @{bf]Oc
fileSplitterFetch.splitterStop(); hX^XtIC=
ka(xU#;
yO !*pC
} tlW}lN}
} bY`k`3v
//负责部分文件的抓取 Uc/%4Gx
**FileSplitterFetch.java cD 1p5U
*/ =Vi+wH{xM
package NetFox; %T&kK2d;
I?1^\s#L
[P<oyd@#
import java.io.*; )t|M)zJ
import java.net.*; (|WqOwmoUt
F:n7yey
(LnKaf8
public class FileSplitterFetch extends Thread { 8r~4iVwg
$+Xohtt
S2`p&\Ifn
String sURL; //File URL >OQ<wO6
long nStartPos; //File Snippet Start Position I!{5*~ 3
long nEndPos; //File Snippet End Position \=w|Zeu{l
int nThreadID; //Thread's ID j_k!9"bt
boolean bDownOver = false; //Downing is over FN G]
boolean bStop = false; //Stop identical NL1Ajms`
FileAccessI fileAccessI = null; //File Access interface rK"x92P0
i`X/d=
vzfWPjpKW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >1W)J3
{ tYVmB:l
this.sURL = sURL; sVGyHA
this.nStartPos = nStart; 9Y0w SOSW
this.nEndPos = nEnd; 6z~6o0s~
nThreadID = id; aK'BC>uFI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U1I2+;"#A
} )!3sB{H
o4U9jU4<"
xV%6k{_:G
public void run() 8BvonYt=8
{ Qv-@Zt!8
while(nStartPos < nEndPos && !bStop) %7O?JI[
{ 85;b9k&\M
#2iD'>bQ
`gKf#f
try{ V]EtwA
URL url = new URL(sURL); t\$U`V)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0|; .6\
httpConnection.setRequestProperty("User-Agent","NetFox"); HK+/:'Pu
String sProperty = "bytes="+nStartPos+"-"; 7^T^($+6s&
httpConnection.setRequestProperty("RANGE",sProperty); "*O4GPj
Utility.log(sProperty); ^*\XgX
hQNe;R5
,.gQ^^+=
InputStream input = httpConnection.getInputStream(); ){r2T1+-%
//logResponseHead(httpConnection); "`[!Lz
WMMO5_Mz
S>.F_Jl
byte[] b = new byte[1024]; ZtHm\VTS
int nRead; FYS/##r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E\;ikX&1
{ vy,&N^P
nStartPos += fileAccessI.write(b,0,nRead); {,OS-g
//if(nThreadID == 1) z6py"J@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M# 18H<]
} =+w*gDr
2YuN~-
0P>OJYFr'
Utility.log("Thread " + nThreadID + " is over!"); wM_c48|d
bDownOver = true; fIGFHZy,
//nPos = fileAccessI.write (b,0,nRead); *._|-L
} rxO2QQ%V
catch(Exception e){e.printStackTrace ();} ) _ I,KEe
} )etmE
} #:3r4J%+~
Mj0Cat=
zW{ 6Eg
//打印回应的头信息 .BTx&AqU
public void logResponseHead(HttpURLConnection con) e/e0d<(1
{ ^o<:;{
for(int i=1;;i++) ioIv=qGdiP
{ c|wCKn}`
String header=con.getHeaderFieldKey(i); 5!fSW2N
if(header!=null) 0yof u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [ET6(_=b
Utility.log(header+" : "+con.getHeaderField(header)); !"4w&bQ
else !awh*Xj6
break; _=`x])mM
} qc!xW,I
} KS!yT_O
993d/z|DX
L@|#Bbmx
public void splitterStop() 0*(K DDv
{ M1=_^f=&.
bStop = true; ;R1B9-,
} .A<sr
m^$5K's&
N2~$rpU3
} +BB0wY
.K9l*-e[=
A|vP$zy
/* rnvQ<671W
**FileAccess.java }z'DWp=uN
*//文件访问(定位，写) 4: sl(r
package NetFox; me./o(!?
import java.io.*; ^tE_LL+ji|
)*[ ""&
J/S{FxNe]
public class FileAccessI implements Serializable{ 7z<Cu<
nUqy1(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oeNzHp_
RandomAccessFile oSavedFile; xYT}>#[
long nPos; _'c+fG \
{,f[r*{Y
^g]xU1] *
public FileAccessI() throws IOException ]C)|+`XE@
{ 3i(Jon/p
this("",0); ]31$KBC
} :`zV [A:D
VG\mo?G
oWD)+5.]
public FileAccessI(String sName,long nPos) throws IOException R92R}=G!
{ ~u2w`H?V
oSavedFile = new RandomAccessFile(sName,"rw"); _?Ckq
this.nPos = nPos; 6h@+?{F.
oSavedFile.seek(nPos); k#jm7 +
} v$JLDt_
CXa Ld7nMX
".M:`BoW4
public synchronized int write(byte[] b,int nStart,int nLen) ]+lF=kkc%
{ {_Np<r;j<
int n = -1; iPkT*Cl8
try{ t[q3{-
oSavedFile.write(b,nStart,nLen); ~,G]glu8
n = nLen; JilKZQmk
} H` Lu"EK
catch(IOException e) Xr2 Wa
{ * 2%oZXF
e.printStackTrace (); YR8QO-7 .)
} /gX%ABmS
:P"9;$FY
]]3Q*bq4
return n; 'yeh7oR
} Uk|9@Auav
)=Y-f?o!
yW:AVqE)t
} v'$ykZ!Z
LiF.w:}
'1lx{UzD
/* T5V$wmB\W
**SiteInfoBean.java b2W;|
*/ xNx`J@xt$
package NetFox; z(r"JNO@
y "<JE<X
~(M*6b
public class SiteInfoBean { " _mmR M
l2r>|CGQ[
fA;x{0CAMX
private String sSiteURL; //Site's URL R,XD6'Q
private String sFilePath; //Saved File's Path br10ptEx
private String sFileName; //Saved File's Name }el,^~
private int nSplitter; //Count of Splited Downloading File Wl?<c uw00
OY$7`8M[
A03I-^0g+
public SiteInfoBean() 5'),)
{//nSplitter的缺省值为5 E=3#TBd
//default value of nSplitter is 5 C?bXrG\
this("","","",5); "rL"K
} Un~]Q?w
t% <pbZO
kK08W3@&t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ya;@<b
{ F1zT )wW
sSiteURL= sURL; 7ucx6J]c
sFilePath = sPath; 6_x}.bkIx=
sFileName = sName; L)@`58Eil
this.nSplitter = nSpiltter; Cx[4 /~_<
VzesqVx
e+wd>iiB
} ,"o\_{<z
Bh?;\D'YC
DZue.or
public String getSSiteURL() OjZ@_V:
{ ,tZwXP{
return sSiteURL; 3>+;G4
} (yfTkBy
D6w0Y:A{.
n[@Ur2&)
public void setSSiteURL(String value) :&m(WZ\
{ lK-I[i!
sSiteURL = value; cu-WY8n
} `f'P
:R)IaJ6)
Qxwe,:
public String getSFilePath() &+v&Dd&
{ 'g#GUSXfj
return sFilePath; o#i{/#oF
} z2V!u\It
Ot?rsr
"q$M\jK#V
public void setSFilePath(String value) T1E{NgK
{ U&6f}=vC
sFilePath = value; EO5Vg
} |fUSq1//
pPE4~g 05h
=["GnL*!0
public String getSFileName() /SiQw7yp%
{ L-XTIL$$
return sFileName; C.@TX
} }^H_|;e1p
<*[(t;i
y.zW>Mfl
public void setSFileName(String value) /vu7;xVG
{ jzQgDed ]
sFileName = value; O'k"6sBb
} YW*ti|u|w
i|t$sBIh
M<SZ7^9<
public int getNSplitter() .FeEK(
{ TtzB[F
return nSplitter; H_{Yr+p
} !59q@Mya[
R#0UwRjeF
C-8@elZ1
public void setNSplitter(int nCount) mwt3EV5
{ L(.5:&Y=`
nSplitter = nCount; PH6uP]
} s^cHR1^
} u!O)\m-
JH 8^ZP:d'
c5JxKU_
/* jN'zNOV~
**Utility.java .k}h'nE
*/ 0VPa=AW
package NetFox; bS*9eX=K
Hg]r5Fe/c
,ecFHkT>
public class Utility { Lx.X#n.]T
KyjN'F$
2gA6$s7
public Utility() OmsNo0OA
{ _f/6bpv
yovC~
~x2azY2DP
} vForj*Xo
ikUG`F%W
//线程睡眠 LBTf}T\
public static void sleep(int nSecond) Gx!Y 4Q}-
{ tks1*I$S<
try{ k/>k&^?
Thread.sleep(nSecond); HUZI7rC[=)
} p~qdkA<
catch(Exception e) n*uT
{ FN\*x:g
e.printStackTrace (); BlnR{Y
} .~u[rc|<
} A`71LV%
t^ Ge"
//日志 FJCs$0
public static void log(String sMsg) g8kS}7/
{ 2{|Z?3FJ^
System.err.println(sMsg); 8 kvF~d ;
} *O_>3Hgl
ia@ |+r
&n9&k Em
public static void log(int sMsg) > 9.%hSy
{ F_G .$aCc
System.err.println(sMsg); agt/;>q\~
} 1%ENgb:8
} qA0PGo
!#d5hjoX
>$,P )cB'
/* ?8N^jjG
**TestMethod.java _iu~vU)r
*/ 't6l@_x
package NetFox; X!_&%^L'
<2N{oK.
A3)"+`&PUl
public class TestMethod { C#-HWoSi
]~2iducB,
eR%\_;}7;
public TestMethod() i\<S ;
{ ///xx/weblogic60b2_win.exe ?r0rY?
try{ fV@[S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )r^vrCNy>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); URceq2_
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3Q'vVNFh<
fileFetch.start(); C$q};7b1N
} A 0v=7 ]
catch(Exception e){e.printStackTrace ();} d?&`ZVl
!KMl'kswe:
yX4Vv{g
} Qo)Da}uo20
$33E-^
<pfl>Uf
public static void main(String[] args) -w*fS,O
{ ^R=`<jx
new TestMethod(); udu<Nis4
} s3eS` rK-
} gUNhN1=
点击下载更多相关资料