http断点续传简单实现（java)

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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)); 54;J8XT7
} 0kQPJWF
for(int i=0;i<nEndPos.length-1;i++) jxaD&4Fs8
{ >KLtY|o)
nEndPos = nStartPos[i+1]; AUVgPXOwd
} b !@Sn/
nEndPos[nEndPos.length-1] = nFileLength; qW:)!z3\
} G|w=ez
} , ^F)L|
GDhE[of
0_P}z3(M
//启动子线程 anw}w!@U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `!:q;i]}
for(int i=0;i<nStartPos.length;i++) 1% F?B-k
{ <$w?/y/'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u cwnA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ev0oO+u
nStartPos,nEndPos,i); w@-PqsF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W6T|iZoV"r
fileSplitterFetch.start(); "vYE+
} @l1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +x?#DH-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $8USyGi3J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m=AqV:%|
nEndPos = " + nFileLength); X{n- N5*
// fileSplitterFetch[nPos.length-1].start(); Ut-B^x)gl
{qW~"z*
P&d"V<
//等待子线程结束 b*;"q9u5
//int count = 0; 2$_9cF Wm
//是否结束while循环 ^,F;M`[
boolean breakWhile = false; `~eX55W
b `2|I {
;4M><OS!
while(!bStop) a07@C
{ tkQH\5
write_nPos(); "'8KV\/D
Utility.sleep(500); .@-9'<K?~
breakWhile = true; ML-)I&>tT
|4mpohX
Cz4)Yz
for(int i=0;i<nStartPos.length;i++) KfBTL!0#
{ _rV5E
if(!fileSplitterFetch.bDownOver) S-31-Zjw
{ ]q-g[e'
breakWhile = false; L@75-T
break; G$'jEa<:u
} v5;I]?72l~
} 9Suu-A
if(breakWhile) B/5=]R
break; g-`~eG28D5
-[= drj9I
svelYe#9z
//count++; yKXff1^M
//if(count>4) e__@GBG
// siteStop(); Ftw;Yz
} l$K,#P<)
AM"Nn L"
)&era` e[
System.err.println("文件下载结束！"); Uie?9&3
} O20M[_S
catch(Exception e){e.printStackTrace ();} e{;OSk`x
} |9"p|6G?B
7&`}~$>}>e
+,:du*C
//获得文件长度 qQpnLV4
public long getFileSize() (>mI'!4d
{ t E` cau
int nFileLength = -1; :Ih|en^w
try{ N=:5eAza
URL url = new URL(siteInfoBean.getSSiteURL()); 0JgL2ayIVI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^mAYBOE
httpConnection.setRequestProperty("User-Agent","NetFox"); ]0;864X0
M :3u@06a
] 2DH;
int responseCode=httpConnection.getResponseCode(); ZYf2XI(_"
if(responseCode>=400) U.AjYez
{ pA{ 5V9
processErrorCode(responseCode); y%sroI('y
return -2; //-2 represent access is error {k4CEt;
} UA[,2MBp
Cv$ SJc
wU#F_De)R:
String sHeader; k>dsw:
^gVT$A
;> m"x
for(int i=1;;i++) &a/__c/l
{ h^ -.]Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2+Px'U\
//Utility.log(in.readLine()); jBaB@LO9G
sHeader=httpConnection.getHeaderFieldKey(i); :'aAZegQY
if(sHeader!=null) 3E f1bhi
{ /-6S{hl9Ne
if(sHeader.equals("Content-Length")) qO`)F8
{ tpy>OT$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6#j$GH *
break; $3Z-)m
} 7PR#(ftz
} B?$ "\;&
else 9N%JP+<89
break; H _Va"yTO6
} nhG J
} "O8gJ0e
catch(IOException e){e.printStackTrace ();} IVlf=k
catch(Exception e){e.printStackTrace ();} ) 'j:
[~:-&
SWp1|.=Sm
Utility.log(nFileLength); zqDR7+]
do uc('@
x{NX8lN
return nFileLength; z} '!eCl
} *m%]zj0bo
$+}+zZX5
FgL,k
//保存下载信息（文件指针位置） +n}$pM|NKU
private void write_nPos() nW"q
{ y*{Zbz#{
try{ Rl|4S[
output = new DataOutputStream(new FileOutputStream(tmpFile)); [i0Hm)Bd3
output.writeInt(nStartPos.length); k%y9aO
for(int i=0;i<nStartPos.length;i++) T0)"1D<l
{ _LwOOZj
// output.writeLong(nPos); A`{y9@h(
output.writeLong(fileSplitterFetch.nStartPos); s:00yQ
output.writeLong(fileSplitterFetch.nEndPos); c*d9'}E
} 3:%QB9qc]'
output.close(); [sW.CK=3
} Og;-B0,A
catch(IOException e){e.printStackTrace ();} EBtLzbj
catch(Exception e){e.printStackTrace ();} yfU<UQ!1
} Yxv9
= 07Gy,=i
(;VVCAoy
//读取保存的下载信息（文件指针位置） `Q+moX
private void read_nPos() kj+#TnF-
{ VL[)[~^
try{ gPC*b+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LJX-AO.4
int nCount = input.readInt(); )} DUMq7
nStartPos = new long[nCount]; pf4 ^Bk}e
nEndPos = new long[nCount]; oJKa"H-jL
for(int i=0;i<nStartPos.length;i++) "m{,~'x
{ 7VK}Dy/Vvn
nStartPos = input.readLong(); .oEmU+
nEndPos = input.readLong(); X0{/ydGF8
} k`".
input.close(); :V)lbn\
} B12$I:x`
catch(IOException e){e.printStackTrace ();} C0=9K@FCb
catch(Exception e){e.printStackTrace ();} y}C`&nW[=
} J/7R\;q`~o
?=GXqbS"
8+mH:O
private void processErrorCode(int nErrorCode) S'dV>m`
{ 6.t',LTB
System.err.println("Error Code : " + nErrorCode); I2(zxq&2M\
} :a:[.
_WX#a|4h{
569}Xbc/
//停止文件下载 $4jell
public void siteStop() +7Kyyu)y@
{ ( *G\g=D
bStop = true; M.h`&8
for(int i=0;i<nStartPos.length;i++) 6)pH|d.FR
fileSplitterFetch.splitterStop(); w@2Vts
reo{*)%
(I@bkMp
} E^w:KC2@
} avmcw~ TF
//负责部分文件的抓取 2/,0iwj-
**FileSplitterFetch.java uH3D{4
*/ 2tayP@$
package NetFox; \b[9ebME
)a}"^1
\U%#nU{
import java.io.*; \b}~2oX
import java.net.*; wPbkUVO
x*oWa,
&iN--~}!$
public class FileSplitterFetch extends Thread { 79zJ\B_
.@iFa3
\qi|Js*{
String sURL; //File URL ]E3U J!!
long nStartPos; //File Snippet Start Position qDWsvx]
long nEndPos; //File Snippet End Position m?s}QGSka
int nThreadID; //Thread's ID # N~,F@t
boolean bDownOver = false; //Downing is over w",? Bef
boolean bStop = false; //Stop identical F#xa`*AP
FileAccessI fileAccessI = null; //File Access interface Ou'?]{
l0*Gb
3CTX -#)vS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4eVI},
{ bIt=v)%$
this.sURL = sURL; 4LI0SwD#^/
this.nStartPos = nStart; >k']T/%
this.nEndPos = nEnd; Hy{ Q#fq
nThreadID = id; $]aBe !
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z?MoJ{.!?R
} x0a.!
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P`U<7xF~
public void run() NV4g~+n
{ PIcrA2ll
while(nStartPos < nEndPos && !bStop) 2EQ6J
{ 0;sRJ
8GJdRL(
.AV)'j#6P
try{ a:SQ16_?
URL url = new URL(sURL); Z:2I/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 33:DH}
httpConnection.setRequestProperty("User-Agent","NetFox"); 5p?!ni9
String sProperty = "bytes="+nStartPos+"-"; `n!viW|tB
httpConnection.setRequestProperty("RANGE",sProperty); '%v#v3'
Utility.log(sProperty); Gt9wR
^SEdA=!
~ aZedQc
InputStream input = httpConnection.getInputStream(); {TXOQ>gY
//logResponseHead(httpConnection); $#o1MX
mxrG)n6Y
vUQFQ
byte[] b = new byte[1024]; 7J>Gd
int nRead; (7lBID4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l#3($QV,
{ s(ROgCO
nStartPos += fileAccessI.write(b,0,nRead); ETv9k g
//if(nThreadID == 1) oFg5aey4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8U~.\`H-PT
} yI:# |w|
Q/_[--0&#
dAx96Og:X"
Utility.log("Thread " + nThreadID + " is over!"); ]pTvMom$6
bDownOver = true; #i QX6WF
//nPos = fileAccessI.write (b,0,nRead); crA:I"I
} QhGXBM
catch(Exception e){e.printStackTrace ();} `ia %)@
} Bt^K]F\
} ~>ME'D~
%@&a7JOL
_3Q8n|
//打印回应的头信息 +2cs#i
public void logResponseHead(HttpURLConnection con) @b!"joEy
{ A3P9.mur
for(int i=1;;i++) k/Mp6<?C:
{ ~M?|Vn
String header=con.getHeaderFieldKey(i); 1`r| op},
if(header!=null) &ju-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DrS~lTf=>
Utility.log(header+" : "+con.getHeaderField(header)); ?s} %
else t> Q{yw
break; x49!{}
} J$uM 03
} ~HLRfL?
5$l9@0D.\
mAqDjRV1
public void splitterStop() sB}]yw
{ $,1dQeE
bStop = true; f%^'P"R
} )jW(6
/dHs &SU,
C77D{@SM
} #*IVlchA"B
;cP8?U
C;1PsSE+A
/* <3 @}Lj
**FileAccess.java $7gB_o$zz
*//文件访问(定位，写) 0TE@xqW
package NetFox; "|LQK0q3
import java.io.*; Q49BU@xX
T@+ClZi
i1*C{Lf;%)
public class FileAccessI implements Serializable{ vx0UoKX
\tt'm\_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SPy3~Db-o
RandomAccessFile oSavedFile; M$#sc`4*
long nPos; c;!g
Vb6K:ZnF
#;j9}N
public FileAccessI() throws IOException 2YQ#-M
{ &{^eU5
this("",0); XDmbm*~i
} u]vPy ria
U~is-+Uq
1 tfYsg=O
public FileAccessI(String sName,long nPos) throws IOException Ygj6(2
{ 3A0_C?E
oSavedFile = new RandomAccessFile(sName,"rw"); fp !:u
this.nPos = nPos; 1t~({Pl<>
oSavedFile.seek(nPos); }Jxq'B
} {Bs+G/?o/
hTS|_5b
]mkJw3
public synchronized int write(byte[] b,int nStart,int nLen) `"<2)yq?
{ p]f&mBO*
int n = -1; MQw9X
try{ u^Sv#K X
oSavedFile.write(b,nStart,nLen); -q2MrJ*
n = nLen; $ad&#q7
} mZoD033H
catch(IOException e) h)B!LAr
{ OXtBJYe
e.printStackTrace (); B3b,F#
} `ut)+T V
}brr ))
_ VKgs]Y
return n; ,?=KgG1i
} E`E'<"{Yd
: ^(nj7D
*FPg#a+
} I)[B9rbe
!A-;NGxE
QWhp:]}
/* Q]i[.ME
**SiteInfoBean.java f)gGH'yOQ
*/ 6o lV+
package NetFox; kkfCAM
elKx]%k*)
x-~-nn\O
public class SiteInfoBean { pI^=B-7
@a;sV!S{
Yk7"XP[Y
private String sSiteURL; //Site's URL twbcuaCTW
private String sFilePath; //Saved File's Path cyc>_$/;1
private String sFileName; //Saved File's Name sFx$>:$
private int nSplitter; //Count of Splited Downloading File %Rn:GK
z\$;'
|0w~P s
public SiteInfoBean() mVrKz
{//nSplitter的缺省值为5 \9jpCNdJ
//default value of nSplitter is 5 "'aqb~j^
this("","","",5); [f(uqLdeM
} #_p
oP-;y&AS
S-,kI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7,su f }=
{ Su4h'&xx
sSiteURL= sURL; G-8n
sFilePath = sPath; rgT%XhUS6f
sFileName = sName; /'`6 ; uRN
this.nSplitter = nSpiltter; 7jR7
rG5i-'
Ys+N,:#R
} R`3x=q
JJNmpUJ
5=.7\#D
public String getSSiteURL() yTj p-
{ uXP- J]>
return sSiteURL; WhenwQT
} scmto cm
3DI^y`av
G4);/#
public void setSSiteURL(String value) 5F03y`@ u
{ `E%(pjG
sSiteURL = value; 5Q;dnC
} [wIKK/O
-g$OOJB6
_X?y,#
public String getSFilePath() z=%IcSx;
{ &08Tns"
return sFilePath; `x< 0A
} &0i71!Oy
* T\>
F]Pul|.l
public void setSFilePath(String value) S#hu2\9D,
{ gm}C\q9
sFilePath = value; dc)wu]
} J;"nm3[.q
\|Y{jG<cu
+E)e1:8
public String getSFileName() `^`9{@~
{ 2}>go^#O/w
return sFileName; }o{!}g9
} L:Ed-=|Uw
TA<hj[-8
P$F#,Cn
public void setSFileName(String value) =^"~$[z(
{ k~ZBJ+ 94
sFileName = value; dvxf lLd @
} %!D_q~"H
&F9OZMK=
{\F2*P
public int getNSplitter() DZF[dxH
{ (c 1u{
return nSplitter; XZ;*>(
} l`oT:
QM7[O]@
A>[hC{
public void setNSplitter(int nCount) @t "~
{ Y9/{0TArG
nSplitter = nCount; S]tkz*w0*
} `7F@6n
} I"~xDa!
+0SW ?#%
HI7]%<L
/* TR+Q4Y:
**Utility.java yr (g~MQ
*/ PlF89-
package NetFox; *C tsFS~
JIB?dIN 1
qW+=g]x\
public class Utility { HarYV :
vRq=m8
[`cdlx?Eh
public Utility() fc["
{ p`pg5R
MP_A<F
|2[S/8g!
} )Fw @afE~
Dg1kbO=2
//线程睡眠 i#Ne'q;T
public static void sleep(int nSecond) ll 6]W~[ZC
{ EaJDz`T}
try{ ~r{\WZ.
Thread.sleep(nSecond); J~M H_N
} 5~v(AB(x
catch(Exception e) .ou!g&xu
{ 8 /5sv
e.printStackTrace (); #_?426Wfs
} z+y;y&P
} BLWA!-
|Gf1^8:C9
//日志 tCd{G c
public static void log(String sMsg) 5@GD} oAn6
{ 3w[<cq.!
System.err.println(sMsg); ~%D^Ga7
} jdV .{8@
CM+F7#T?n
nNd`]F^U
public static void log(int sMsg) j;$6F/g
{ ]J8KCjq@
System.err.println(sMsg); G5y]^P
} 82G lbd)
} >DPds~k
V:nMo2'hb
H={O13
/* n1fEdaa7g
**TestMethod.java {QIS411
*/ !N@S^JD6
package NetFox; z }FiU[Hs
UrD=|-r`
;PuyA
public class TestMethod { U-wq- GT
9~LpO>-
Wq=ZU\Y
public TestMethod() lGD%R'}
{ ///xx/weblogic60b2_win.exe 1(#*'xR
try{ b#?ai3E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *qeic e%E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bIvJs9L
SiteFileFetch fileFetch = new SiteFileFetch(bean); uzzWZ9Tv
fileFetch.start(); yv6Zo0s<J
} mq|A8>g
catch(Exception e){e.printStackTrace ();} }1X11+/W
Wto@u4
`'A(`. CL
} CF4Oh-f
i?1js! 8
qK9L+i
public static void main(String[] args) J};u25:}
{ A{DIp+
new TestMethod(); WI*^+E&=*
} c%xED%X9
} F]URf&U
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